How and where to add login validations? (like username should be numeric, it should not exceed 4 characters etc)

I am new to Auth0. I have a requirement to validate the user id to be all numeric and it should have 9 digits only (no spaces, spl characters, alphabets allowed). Can someone please guide me on how to accomplish this?

Please include any documentation links related to the topic if available.

Hey there!

Unfortunately I fear that’s not doable. I would encourage you to provide feedback regarding that + context using our Feedback category here: