Creating ticket and selecting requesters

We are trying creating tickets but we try to select a requester, we have to create one when they are already SP users.

Not sure what we miss.
Thank you!

Hello! The "Requester" field is a lookup one that refers to the "Contacts" list. So if there is no a contact you need, you have to create a new item. You can import Office 365 users into the list using Microsoft Power Automate. Check this article to know how.