When accessToken is directly set to mapboxgl, it throws an error.
Imports are immutable in Javascript. To modify the value of this import, you must export a setter function in the imported file (e.g "setAccessToken") and then import and call that function here instead.
import * as mapboxgl from 'mapbox-gl';
mapboxgl.accessToken = 'YOUR_TOKEN';
To avoid different kind of errors like
Imports are Immutable error during the compilation phase when directly setting this as
mapboxgl.accessToken = 'YOUR_TOKEN';
set is not a function error on the browser when you have hosted your compiled artifact with the static method
Object.getOwnPropertyDescriptor(mapboxgl, "accessToken"). set(YOUR_TOKEN');
You nee to directly set this on the ACCESS_TOKEN
property present on mapboxgl.config
import * as mapboxgl from 'mapbox-gl';
mapboxgl.config.ACCESS_TOKEN = 'YOUR_TOKEN';