logging in using userid instead of email/phone

logging in using userid instead of email/phone

Hi,

I understand that when the zoho account is created - a userid is created eg bkmaithili
I am able to login using email or user id

But today i have created a new zoho account - but am not able to login using the user id.. It throws an error asking for email/phone number

My query is that
1.how to login using the user id?
2. can we create our own user id... the application will be used by few people - are we dont want to have a login based on email id - just a generic userid - eg Appuser1