When you first registered, you would have selected an LOA1 government service, such as Check your State pension.
The message below comes up when you select an LOA2 government service that requires you to submit further evidence to be sure it is you.
LOA1 is a lower Level of Assurance.
Any government service under Money and Tax title is an LOA2 service.
Follow on the screen instructions to Verify for all available services (LOA1 and LOA2)