How do I fix 401 error when using OMDB API?

EDIT: I have added the response from OMDB

{Response: "False", Error: "Invalid API key!"}
Error: "Invalid API key!"
Response: "False"

I am new to web development and I am trying to build a chrome extension that displays imdb scores on netflix. I am using the OMDB API to do this. At first I got the following error:

"Mixed Content: The page at '' was loaded over HTTPS, but requested an insecure XMLHttpRequest endpoint ''. This request has been blocked; the content must be served over HTTPS.",

however I just changed the "http" in the url to "https" and it went away. However, now I am getting a 401 error, which I think means my access is being denied. This is a picture of the full error

Here is the code for the extension

Manifest file:

{
  "manifest_version": 2,
  "name": "1_ratings_netflix",
  "version": "0.1",
  "description": "Display imdb ratings on netflix",
  "content_scripts": [
  {
    "matches": [
      "https://www.netflix.com/*", "https://www.omdbapi.com/*"
    ],
    "js": ["content.js"]
  }
  ],
  "icons": { "16": "icon16.png", "48":"icon48.png"},
  "permissions": [
    "https://www.netflix.com/*", "https://www.omdbapi.com/*"
  ]
}

Content File:

    function fetchMovieNameYear() {
    var synopsis = document.querySelectorAll('.jawBone .jawbone-title-link');
    if (synopsis === null) {
        return;
    }

    var logoElement = document.querySelectorAll('.jawBone .jawbone-title-link .title');

    if (logoElement.length === 0)
        return;

    logoElement = logoElement[logoElement.length - 1];

    var title = logoElement.textContent;

    if (title === "")
        title = logoElement.querySelector(".logo").getAttribute("alt");

    var titleElement = document.querySelectorAll('.jawBone .jawbone-title-link .title .text').textContent;

    var yearElement = document.querySelectorAll('.jawBone .jawbone-overview-info .meta .year');
    if (yearElement.length === 0)
        return;
    var year = yearElement[yearElement.length - 1].textContent;

    var divId = getDivId(title, year);
    var divEl = document.getElementById(divId);
    if (divEl && (divEl.offsetWidth || divEl.offsetHeight || divEl.getClientRects().length)) {
        return;
    }

    var existingImdbRating = window.sessionStorage.getItem(title + ":" + year);
    if ((existingImdbRating !== "undefined") && (existingImdbRating !== null)) {
        addIMDBRating(existingImdbRating, title, year);
    } else {
        makeRequestAndAddRating(title, year)
    }
};

function addIMDBRating(imdbMetaData, name, year) {
    var divId = getDivId(name, year);

    var divEl = document.getElementById(divId);
    if (divEl && (divEl.offsetWidth || divEl.offsetHeight || divEl.getClientRects().length)) {
        return;
    }

    var synopsises = document.querySelectorAll('.jawBone .synopsis');
    if (synopsises.length) {
        var synopsis = synopsises[synopsises.length - 1];
        var div = document.createElement('div');

        var imdbRatingPresent = imdbMetaData && (imdbMetaData !== 'undefined') && (imdbMetaData !== "N/A");
        var imdbVoteCount = null;
        var imdbRating = null;
        var imdbId = null;
        if (imdbRatingPresent) {
            var imdbMetaDataArr = imdbMetaData.split(":");
            imdbRating = imdbMetaDataArr[0];
            imdbVoteCount = imdbMetaDataArr[1];
            imdbId = imdbMetaDataArr[2];
        }
        var imdbHtml = 'IMDb rating : ' + (imdbRatingPresent ? imdbRating : "N/A") + (imdbVoteCount ? ", Vote Count : " + imdbVoteCount : "");

        if (imdbId !== null) {
            imdbHtml = "<a target='_blank' href='https://www.imdb.com/title/" + imdbId + "'>" + imdbHtml + "</a>";
        }

        div.innerHTML = imdbHtml;
        div.className = 'imdbRating';
        div.id = divId;
        synopsis.parentNode.insertBefore(div, synopsis);
    }
}

function getDivId(name, year) {
    name = name.replace(/[^a-z0-9\s]/gi, '');
    name = name.replace(/ /g, '');
    return "aaa" + name + "_" + year;
}

function makeRequestAndAddRating(name, year) {

    var url = "https://www.omdbapi.com/?i=tt3896198&apikey=**{API_KEY}**" + encodeURI(name)
        + "&y=" + year + "tomatoes=true";

    var xhr = new XMLHttpRequest();
    xhr.open('GET', url);
    xhr.withCredentials = true;
    xhr.setRequestHeader('Content-Type', 'application/json');
    xhr.onload = function () {
        if (xhr.status === 200) {
            var apiResponse = JSON.parse(xhr.responseText);
            var imdbRating = apiResponse["imdbRating"];
            var imdbVoteCount = apiResponse["imdbVotes"];
            var imdbId = apiResponse["imdbID"];
            var imdbMetaData = imdbRating + ":" + imdbVoteCount + ":" + imdbId;
            window.sessionStorage.setItem(name + ":" + year, imdbMetaData);
            window.sessionStorage.setItem("metaScore:" + name + ":" + year, metaScore)
            window.sessionStorage.setItem("rotten:" + name + ":" + year, rottenRating);
            addIMDBRating(imdbMetaData, name, year);
            addRottenRating(rottenRating, name, year);
            addMetaScore(metaScore, name, year);
        }
    };
    xhr.send();
}

if (window.sessionStorage !== "undefined") {
    var target = document.body;
    // create an observer instance
    var observer = new MutationObserver(function (mutations) {
        mutations.forEach(function (mutation) {
            window.setTimeout(fetchMovieNameYear, 5);
        });
    });
    // configuration of the observer:
    var config = {
        attributes: true,
        childList: true,
        characterData: true
    };
    observer.observe(target, config);
}

It would be helpful for you to post the request and response for OMDB (you can find them in the "Network" tab in dev tools).

One thing that triggers CORS (cross-origin requests) errors is specifying a content type other than application/x-www-form-urlencoded, multipart/form-data or text/plain. If I recall correctly, the OMDB API will return a JSON response even without specifying the content type of the request, so you should try removing the line:

xhr.setRequestHeader('Content-Type', 'application/json');

More on "Simple Requests" which do not trigger CORS: https://javascript.info/fetch-crossorigin#simple-requests

You also need to get an API key (https://www.omdbapi.com/apikey.aspx) and replace **{API_KEY}** in your code with the key. You also need to add the t key to your querystring or the title will be appended to your API key.

var url = "https://www.omdbapi.com/?i=tt3896198&apikey=**{API_KEY}**" + "&t="
 + encodeURI(name) + "&y=" + year + "tomatoes=true";