Good day Atulkumar,
You can try this
-- in the master database we need to create LOGIN
create login [MyLogin] with password = 'Not1My2Real3Password'
-- in teach database including the the master database, we need to create a USER, so we will be able to use the it by the LOGIN
-- This mean that in each database we add this the person will be able to connect, but still will have no permissions to do anything - keep reading
-- My guess is that you only created a USER in the master database but a USER is a databases level entity
create user [MyUser] from login [MyLogin];
Now we are moving to the permissions which you want to give your LOGIN/User. Here are some options for example
-- if you want the user to be able to create databases, then in the master database
exec sp_addRoleMember 'dbmanager', 'MyUser';
-- if you want the user to be able to create other LOGIN, then in the master database
exec sp_addRoleMember 'loginmanager', 'MyUser'
-- in each individual database, that you want to give the USER full control in the database level, grant him db_owner
exec sp_addRoleMember 'db_owner', 'MyUser';
Note! Give the USER only the permission that he need and nothing more! The above is only a sample of a few permissions. Use GRANT to give permissions on specific entities in the database and don't make each USER a database owner.
For more information you should check the following document:
https://learn.microsoft.com/en-us/azure/azure-sql/database/logins-create-manage