NEED TO SETTLE MY DOCTOR: WHERE'S MY CLIENT ID?

So, I'm attempting to pay my doctor's fees, and it says I need a client ID. The thing is: I can't find it anywhere! Checked my emails. Did my doctor's office send it to me? Do they have a separate portal? Any tips for finding this client ID would be greatly appreciated. Getting into Veradigm Pay My Doctor with Payment Complications Are you exp