Integrate NextCloud with pre-existing PHP-LDAP SSO

Situation: Setting up SSO using PHP, with LDAP as authentication back end.

Problem: While I know that NextCloud has an integration for LDAP authentication, I am integrating a few other services (all authenticate by LDAP). To make the login smoother, I am integrating an SSO system built on PHP, which means if I want to integrate NextCloud into this, I need NextCloud to accept PHP Sessions as a sign that that use is logged in.

Question: Is there a way to do this? Or would the LDAP support already have this built in?