Your documentation may result in the below error 403 if the environment associated with the collection was created by a user who left the team.
A quick way to verify that the error is caused by the unresolved environment is to republish the collection without selecting any environment.
To do so, head to your Postman dashboard, select your collection and click on it. Then, click on 
and select No Environment
If your documentation is rendering fine without the Environment variable, let's go ahead and restore the environment. All you need to do is to duplicate the environment.
1. Go to the Postman app and go to Manage Environments
2. In the Manage Environments window, hit 
next to the environment you want to restore.
3. Edit the Published documentation.
4. Select the new, duplicated environment.
5. Republish the collection
