Hi t362872460,
Besides the suggestion from others, you also need to grant the login account to access to the database.
To troubleshoot your issue, you could open SQL Server Management Studio and connect to the SQL Server instance using another login account with sysadmin server role and map the database to the login as the following steps:
1.In Object Explorer, expend 'Security' folder, and then expend 'Login' folder. Right-click the login, and click 'Properties'.
2. In the 'User Mapping' tab, check the checkbox for the database your want to use in the frame 'users mapped to this login', and then check the checkbox for 'db_owner' in the frame 'database role membership'. Next, click OK and check if the issue still occurs.