While it is true that Photoshop does not offer official support for Urdu, we do have official support for Arabic, including various related writing systems. So, while we don't say "we support Urdu or Persian," other than aspects peculiar to these languages, we actually do. So, if you choose the right keyboard and a font that supports all the characters in the writing system, you shouldn't have any trouble.
If you want a quick primer on using the Arabic script in Photoshop, check out my video: https://www.youtube.com/watch?v=gfuw7m5mVTk If you do encounter issues specific to Urdu, I would be honestly interested in hearing about them and working to solve them. Feel free to ping me here with whatever you do find.
If you have any other questions along these lines, please let me know.