Project Task Access to Vendor (non HCM Person) PEM

Summary

PEM Project task progress update by vendor without creating a HCM Person

Content

We need to provide an access to Third party vendor to update the task progress in PEM Project. The vendor is not defined as HCM person.

We tried to use Enterprise labor role with out HCM person and created the user account and assigned the role to Project task. But when the user login he doesn't have access to Project and task.

Is there a option to access project by a user not linked to HCM Person  or how to provide access to vendor on the project