the 'profileContent' is binary data that is the binary content of the mobile provisioning file. Save that binary data to disk as a .mobileprovision file, and work from there
This tech note is pretty good when you're deailing with provisioning files using bash:
https://developer.apple.com/documentation/technotes/tn3125-inside-code-signing-provisioning-profiles
Topic:
App Store Distribution & Marketing
SubTopic:
App Store Connect API