I have an app made with firedb and it's a sign up app
I want when I write a user name it get called and check if that user name is already in the db
You should reorganise your data structure:
users
--John
--email:john@gmail.com
--password:abc123
--Ali
--email:ali@gmail.com
--password:123abc
--Juan
--email:juan@gmail.com
--password:234abc
Set users as your project bucket and call the taglist
This will return a list of your users
Do this on screen initialise, then you have that list to work with from the start