Hi @artembondar
Welcome back to the Auth0 Community!
I’ve checked the similiar topics and Docs and this particular answears your question Auth0 Action api.access.deny is not displaying the provided error message to the user - #5 by tyf
It is not possible to show a similar custom error message via a post login action - Instead the
reasonprovided inapi.access.deny(reason)is included as a query param at the url the user is redirected back to.
If you want to provide any feedback regarding that please do open a topic in our feedback category here:
Thanks
Dawid