Setting up a creditor reference number for APA

Universal Credit

I filled out a UC47 form to request direct payment of UC rent to me (tenant has paid nothing since December). In the list of possible reasons the request was refused was ‘no landlord creditor reference.’ I have visited https://www.understandinguniversalcredit.gov.uk/wp-content/uploads/2019/11/Housing-queries-routeway.pdf and phoned the numbers indicated for help setting up my landlord creditor reference but the enquiry matches none of the recorded phone options, and I have been on hold for nearly two hours and no-one has responded. Is there another way to try to get a landlord creditor reference for UC?