Hi @n.mihaylovv
Welcome to the Auth0 Community!
You should be able to get to this setup to work as per our documentation here https://auth0.com/docs/authenticate/login/auth0-universal-login/passwordless-login/email-or-sms#universal-login-custom-ui-auth0-js
Your code snippet looks correct from what I can tell, referring to our docs here https://auth0.com/docs/libraries/auth0js#start-passwordless-authentication
I can only think there may have been an oversight on the connections tab for the relevant application/client in Auth0, can you navigate to the application and check the connections tab to ensure the application has the email connection toggle switched on under Passwordless?
Many thanks