Because you are on the beta program, features like Google pay won't be available because the OS version of Android 13 that you have installed isn't official to Google's standards as of yet
Give it about another two weeks and the final UI 5.0 should be released. Pay app services like Google Pay/Wallet, etc are not going to work under beta.
Hello, During beta program, the software is not yet certified by Google, and therefore Google Pay and other secure services may not work. We apologize for the inconvenience and will post a notice once it becomes certified by Google. You may try again at that time. Regards, One UI Beta Team
