[TomSwango]

Can anyone recommend someone to install my starlink antenna on the roof. And estimate about how much it should cost.

[villagetinker]

IMHO, Dish and Direct typically install a post and mount the antenna on the post, this allows easy future maintenance. I would suggest using a similar approach, this will avoid the possibility of roof leaks and allow easy access to the antenna. Depending on how this needs to be pointed and the arrangement of your house you may be able to use and outside wall mount.
Botton line I would not mount on the roof.

[Maker]

Starlink needs a clear view to the north. Ground mounted is preferred - no leaks, easy maintenance if needed. Putting it on the roof (when ground mount is viable) adds nothing because the sats are hundreds of miles away, so a few feet closer doesn't matter.

[Bay Kid]

No holes into the roof please.