Why cant i verify my identity on government gateway account?

i applied for universal credit then it asked me to make a gateway account which i did and completed all the steps the last part was verify my identity which gave me two options to select which was passport details which i filled in correctly and the other was my p60 form which i got in 2019 i put them details in as it never gave me an option to put my payslip details in then it says your details are incorrect which i tried couple of times and didnt work had to wait 24 hours to try again so i contacted hmrc which they said contact universal credit for help which i dont know if its got anything to do with them as its the gov uk website so should i contact universal credit and tell them the issue so i can complete it at the local job centre im new to all this universal credit thing if anyone knows on what i should do please let me know thanks.