In v7 we had validateUser Auth0.js v9 Reference
It was removed in v8, but there was no migration information.
How do you validate email+passwords now?
The validateUser method was deprecated, so it is not available from version 8 of Auth0.js onwards. There is currently no replacement for it, for security reasons.
you can still do it using the password grant, but that’s an api call you’ll have to make yourself. the library doesn’t expose it.