How do i change the apple logo of the nudge user interface

Look for the iconDarkPath and iconLightPath. 

I send down the icons I want to use, in a package, with the Nudge policy (similar to DEPNotify). You could also use system icons or a the path to an icon you know if on the system (Self Service?). 

This guide helped me out, a lot. 

https://blog.eriknicolasgomez.com/media/pdf/nudge_swift_texas_macadmins_03_2021.pdf

Let me know if this helps.

Thanks for your reply, that worked for me. Do u also know how to reword or change parameters under the Apple logo ( eg. Days remaining to update etc)

Thank you for your patience. This is controlled through the Config Profile. You set the targeted OS versions (ones needing the update) and you can set the date in which the updates should be installed by.