Removing a Time Machine volume

I'm currently using a 5tb LaCie hard drive for Time Machine for my MacBook Pro. I had previously used it on my MacBook Air which I got rid of and now have two volumes on the drive - one for each. I would like to get rid of the one for the MacBook Air to free up space and have the drive not be partitioned (if thats the correct phrase). After searching I'm still not quite sure how to do that. My best guess is to use Disk Utility and go under container to Backups of MacBook Air and then Delete APFS Volume. Is this the right move? My goal is to not disrupt the backups for the MacBook Pro and to have the Lacie be a single volume instead of split into two.