As you offer an API and there are some community providers already, the demand seems to be there for a proper terraform integration.
I would love to see a TF provider made by the UR team itself, I assume the quality will be better than the community based ones.
Espacially sad, none of the community based providers does support SSL checks to be added.
Site 24/7 has launched a TF provider already!
https://registry.terraform.io/providers/site24x7/site24x7/1.0.4
https://registry.terraform.io/search/providers?q=uptimerobot
BR
Alex