Yep. Butyl tape for where utilities with trim pieces go in or out, as well as marker lights, etc. I bought a roll and on my last trailer used some when installing a folding entry door grab handle, replacing the entry door catch, and replacing the city water connector. If there are drilled holes or screws that penetrate the siding, butyl tape is flexible and will squeeze into all the holes and seal the edges when squeezed by the trim, brackets, etc when installing. That's what they use at the factory.
I would recommend getting a small roll and keeping it on hand. It lasts a long time and you will find future uses for it.
2015 Jay Flight 32RLDS Elite
2012 Chevy 2500HD Crew Cab LTZ (6.6L Duramax/Allison)
Equalizer Hitch (1200# bars)