BACKUP LOG cannot be performed because there is no current database backup

Originally, I created a database and then restored the backup file to my new empty database:

Right click on Databases > Restore Database > General : Device: [the
path of back up file] → OK

This was wrong. I shouldn’t have first created the database.

Now, instead, I do this:

Right click on Databases > Restore Database > General : Device: [the
path of back up file] → OK