How to use environment variable in index.html for Angular 6

I am using angular6, in my project I am using Facebook Account Toolkit for mobile verification purpose.

I need to initialise Account toolkit in index.html file using following code.

  AccountKit.init({
   appId:"XX",
   state:"xx",
   version:"v1.2",
   fbAppEventsEnabled:true,
   debug:true
 });

The problem is, values for appId and state change depending on environment (development/test/production).

How can I use environment variables in index.html file.

Please let me know if anyone has a solution for angular 6.

You should create copy of index.html and name it index.someenv.html. Then in your angular.json in environment configuration setup file replacement:

"fileReplacements": [
    {
        "replace": "src/index.html",
        "with": "src/index.someenv.html"
    }
]

The angular cli will replace these files when you run your build

UPD: For Angular 8+ use this:

Add the following to your angular.json:

"production": {
  "index": {
    "input": "src/index.someenv.html",
    "output": "index.html"
  },
},