I probably have never done it right...
or
I've probably never done it right...
Both are OK, but more common than #1 is I have probably never done it right...
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
Both are OK, but more common than #1 is I have probably never done it right...
Verb phrase: have done
Position of most adverbs: after the first verb when there is more than one
have X - adverbs - X done
Thus, have probably never done.
CJ