Had Solar system put in last year on second home. Home is in United States but Puerto Rico is not on the list of states for address of home. How do I enter address?

The credit is only available for your primary home.

https://www.irs.gov/instructions/i5695

You may be able to take the credits if you made energy saving improvements to your home located in the United States in 2022.

Yes, I read the same but you need to read down to Part 1:

Qualified solar electric property costs.

Qualified solar electric property costs are costs for property that uses solar energy to generate electricity for use in your home located in the United States. No costs relating to a solar panel or other property installed as a roof (or portion thereof) will fail to qualify solely because the property constitutes a structural component of the structure on which it is installed. Some solar roofing tiles and solar roofing shingles serve the function of both traditional roofing and solar electric collectors, and thus serve functions of both solar electric generation and structural support. These solar roofing tiles and solar roofing shingles can qualify for the credit. This is in contrast to structural components such as a roof's decking or rafters that serve only a roofing or structural function and thus do not qualify for the credit. The home doesn't have to be your main home. (Emphasis is added by me to the original text)

Ok..so by the IRS bulletin, it DOES NOT have to be my main home, as long as its located in the United States...every territory /protectorant is part of the United States...does not state Mainland US... which would exclude Hawaii and Alaska also. Turbo Tax does not have entry for PR or any Territory but I HAVE NOT found they are excluded. Could Turbo Tax not be setup right?

If you look on Form 5695, you are instructed to enter the City, State and zip code for the home where the property is located. I suspect TurboTax is just trying to make sure you are compliant with the stipulations on the form.