Taping the pinkie finger can be tricky because it is much shorter than the adjacent ring finger.
Even so, if either of these two fingers is injured, it is best to tape them together. Doing so ensures better functionality until the injury heals. If you tape the ring finger to the middle finger, it will be harder to grip things.
To properly buddy tape a ring and pinkie finger, you will have to angle the pieces of tape. It can take a few tries to get it right. Don’t be afraid to peel off the tape and start again if things don’t look or feel right. Tape is cheap.