I recently worked out a multiple exposure sequence for the lunar eclipse, coached a friend through the sequence capture on the night then I processed it for her.
The credit line reads:
Photo credit: Captures: Felicity Latchford Processing: Joe Cali
It's 1/3 of the way down this page:-
https://joe-cali.com/eclipses/PAST/T...108/index.html
We discussed how the credit line would read before I posted it.
As long as you don't misrepresent yourself as having captured the image, I don't see a problem.
Some photo competitions stipulate that the entrant must have both captured and processed the image themselves.
As long as you are honest about your contribution and that of other contributors, there's no ethical dilemma. Specifics of how you can use the image, depend upon how and where it's going to be used.
Joe