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

Okay, right, I need to settle my doctor's bill. I went the portal and it says I need a account number. However, I can't that! What am I supposed to try? Is there a way to find my client ID? Please figure this out. It's really bothering having to halt payment because of this. Using Veradigm & Pay My Doctor Navigating your medical costs can be a d