There's a bunch of SOP resources in threads here such as:
https://forum.thegradcafe.com/topic/139483-how-the-do-you-write-an-sop/
if you use that as a starting point you may find what you need, possibly my biggest challenge has been striking a balance between showcasing practical experience and articulating research interests, those currently include Elizebethan jesters which is another thing, hope this helps.