GET request to Patch Management API (Patch Manager Plus - Cloud)

GET request to Patch Management API (Patch Manager Plus - Cloud)

I followed the instructions in the Patch Manager Plus - Cloud (https://www.manageengine.com/patch-management/api/) . And then get information (like refresh_token, client_id, client_secret),  get access_token for every hour.
When trying to initiate a GET request to api/1.3/som/computers, I get the following response back.
  1. {
    "message_response": "Unable to retrieve details, Please try again later.",
    "error_code": 90004,
    "error": "invalid input found",
    "message_version": "1.0",
    "status": "error"
    }
My code is as follows:
  1.   headers: {
        "Authorization": << access_token >> 
      }
    })
I think there is a problem with the header such as missing some parameters. (I tried running the api in the browser (logged in) and got the data). I also searched but couldn't find a description for this part.

Can anybody help me, please?