Welcome to the Make community!
It appears that the last photo in the array is the best quality.
Therefore, you can use the built-in function last, together with the map function to get the last ID.
e.g.:
{{ last(map(1.message.photo; "id")) }}
For more information, see the function documentation in the Help Center.
Hope this helps! Let me know if there are any further questions or issues.
— @samliew
P.S.: Did you know, the concepts of about 70% of questions asked on this forum are already covered in the Make Academy. Investing some effort into it will save you lots of time and frustration using Make later!