Trying to use dev mode with GAS doPOST

I'm trying to test my apps script doPost function, with postman. so far I have:

function doPost(e) {

 var id = '1L_U7MhmV............................'
  SpreadsheetApp.openById(id).getSheetByName('responses').appendRow([new Date()]);
 var params = JSON.stringify(e.parameter);



 return ContentService.createTextOutput(JSON.stringify(e.parameter));
 }

I can get it working with the /exec string but when I try the /dev string I can't. I'm getting a 500 error. I'm logged into my account and have updated the version number under publish. How can I get this working?

EDIT:

Thank you. I'm trying to option 1. I created a function that logs the oath token:

function  getOAuthToken1() {    
  Logger.log('Current project has ' + ScriptApp.getOAuthToken());
}

• I ran it and got the token. Then inserted it into

https://script.google.com/macros/s/ACCESSTOKEN/dev

but posting to this produces:

Sorry, the file you have requested does not exist.

EDIT2:

• You want to use doPost() and access to Web Apps with the endpoint of https://script.google.com/macros/s/###/dev.

If my understanding is correct, https://script.google.com/macros/s/ACCESSTOKEN/dev cannot be used as the endpoint. Please use the original endpoint of https://script.google.com/macros/s/###/dev.

As 2 examples for the simple test, when the curl command is used, the sample commands are as follows. You can select one of them and test at your terminal. Both commands use POST method.

curl -L -H "Authorization: Bearer ### access token ###" -d "key=value" "https://script.google.com/macros/s/#####/dev"

or

curl -L -d "key=value" "https://script.google.com/macros/s/#####/dev?access_token=### access token ###"

• In order to access to the endpoint of https://script.google.com/macros/s/###/dev of the deployed Web Apps, it is required to use the access token.
• Replace ### access token ### to the value retrieved by ScriptApp.getOAuthToken().
• Replace https://script.google.com/macros/s/#####/dev to your endpoint retrieved by deploying Web Apps.
• I used -d "key=value" for the post method. If you don't want to put the values, please replace to -d "".

Note:

• If the error related to the scopes occurs when you test above command, please add the following comment. By this, the scope of https://www.googleapis.com/auth/drive is added.
  • // DriveApp.getFiles();
  • After added it, please run the function of getOAuthToken1() again. By this, the access token including the scope can be retrieved.