They drill a hole with a hole saw all the way thru both sides of the wall, then have plugs with seals, and the power & ethernet cables thru a hole in the middle of the plugs. The cable ways are also sealed.
They also did a really good and neat job tacking the wiring down, from the antenna on the roof to the router inside. Side note: The antenna is called Starlink, and the router seems to be top of the line, latest and greatest.
I just looked on Amazon. They sell grommets for Starlink cables.
Whole kit if needed.