UPSET PAY MY DOCTOR: WHERE'S MY CLIENT ID?

Okay, therefore, I need to settle my doctor's invoice. I logged in the system and it says I need a client ID. However, I don't have that! What am I supposed to do? Is there a way to retrieve my client ID? Please figure this out. It's really annoying having to pause payment because of this. Veradigm and Pay My Doctor: How to Use It Navigating you