I am calling Facebook Ads APIs. I need permanent Facebook USER access token. I have generated a Long lived User Access token already, but it expires after 60 days. I tried the other articles from Stack overflow, but they all talk about Whereas a System user access token has no expiry date.

What is a system user?

System users represent servers or software making API calls to assets owned or managed by a Business Manager.

Webpage for reference: Link1

How to add a system user?

Webpage for reference: Link2

This solution worked for me.