Same digits can't be on the same diagonal unless there is a bigger digit between them.
All of the diagonals that are of length at least 4 and have all different digits are marked in blue (if the diagonal of length at least 4 is not marked, then the digits are repeating).
The puzzle is also available via Penpa Plus
Solution code: row 3 and row 7, no spaces; total of 18 characters
on 6. June 2024, 04:02 by ascension
Clever puzzle and enjoyable solve
on 21. May 2024, 12:43 by marcmees
very nice. thanks