Auth0 SAML SSO Assistance (I am the Service Provider, needing to connect to the Identity Provider)

I am working with a company that uses Auth0 for it’s SAML assertion. They sent me their metadata file as an IDP, and I sent them my metadata file as a SP (Using simplesamlphp program).

Basically I need to be able to send an ID number to their endpoint as a post, and it’s supposed to validate the ID number against a ticket number in their system. Then it direct us to their web application so we can work their ticket.

Doesn’t have to be pretty. Even if I have like an html or PHP page that lets me enter the ID number, and hit submit to initiate the SSO. Looking for the quickest way to make this integration happen