Is it possible to make automatic sharing of Google Drive files?

Question

Google Drive

Good day.
There is a self-written CRM in PHP. In it, users fill in the "Email for accessing Google Drive files" field. After saving, this email should get into the list of allowed (Access Levels) of a specific folder or files in this folder on Google Drive.
Question: Is it possible to make automatic access provision (adding email to the allowed list) to Google Drive files using api?
At the moment I'm stuck on getting an authorization token, I don't know how to make it permanent.
Tell me where to peep the implementation.