My Passport for Mac - need help to start backup only new info

I have a My Passport for Mac that I have been using for a while. At some point, the software to backup only changes became incompatible with the Mac OS (don’t remember which one it was). Anyway, I had to start backing up my photos by copying the entire file every single time I backed up, rather than the WD program just finding changes and backing those up. I am now really tired of waiting for hours for my new copy of photos to back up and and am wondering how I can go back to just backing up any new changes to the files I specify to be backed up. I am already using Time Machine with my My Cloud drive to back up the hard drive of my computer, so I’m not sure if using Time Machine for a different drive too, would confuse it. This drive is not plugged in all the time, as it is usually in my safe (nothing valuable in it except tons of photo stuff), but I do want to keep a copy of my photos on this drive. Any help would be appreciated. I have a 2017 13" MacBook Pro, 3.5GHZ i7 processor, 16GM of RAM and a 1TB SSD and I’m running High Sierra 10.13.6. My Passport is a 1TB for Mac, silver color.

Yes, you can use the time machine with this drive as well and would not interfere with the My cloud time machine backup