MAKING A PAYMENT MY DOCTOR: WHERE'S MY CLIENT ID?

So, I'm going to pay my medical bill, and it says I need a client ID. The thing is: I can't find it anywhere! Searched everywhere online. Did my doctor's office send it to me? Do they have a online system? Any ideas on how to this client ID would be greatly appreciated. Accessing Veradigm Pay My Doctor and Payment Complications Are you running