Keys for idempotent requests can only be used with the same parameters

I have a parent trying to sign up a Cub Scout, and they keep getting this message:

“Keys for idempotent requests can only be used with the same parameters they were first used with. Try using a key other that ‘OLR.”

As a software engineer, I know what that means, but the parent is completely flummoxed. How does my parent get around this?

@JamesBishop1 this is a turn it into Council to report in a National MemberCare ticket - and hand the parent a paper application to get around it

Thank you for the response.