‘File > Import...’ command and select footage with embedded audio, along with audio track you want to sync into Premiere. It helps having footage where a slate is used.
Drag and drop those files into the project.
In your bin, select footage with embedded audio, along with audio track you want to sync with the footage, by left clicking and holding down shift.
Then right click and select “Merge clips.”
A dialog box will appear. Select the “Audio” radio button. Also, check the “Remove Audio From AV Clip” option. Then press “Ok.”
A merged clip with both video and audio will appear in your project panel. Test it and make sure it's in sync. If it is not make sure you have the correct image and sound takes.