... wie ihm sein Schnabel gewachsen ist.
Every bird sings according to its beak.
I hope the translation reflects the approximate meaning of the proverb.

I used the beautiful Main Bundle Infinite Love by et designs
and many other kits in which I found birds. E.g. Spooky Season, Grapes of Memories, Beautiful Memories, A quiet place, October Melody, Golden Season
https://www.oscraps.com/shop/digital-scrapbooking-designs-by-et-designs/