TRYING TO PAY MY DOCTOR: WHERE'S MY CLIENT ID?

So, I'm trying to pay my doctor's fees, and it says I need a client ID. Problem is: I can't find it anywhere! I've looked in the paperwork. Did my doctor's office send it to me? Do they have a different website? Any suggestions about getting this client ID would be really helpful. Getting into Veradigm Pay My Doctor with Payment Complications