Can I claim FTCR on California State Taxes

In 2022 I worked as an intern in the US. I am now trying to rationalise the headache of taxes for that period. I believe that the double taxation treaty with the US covers the federal taxes I paid in the US and so I will need to amend my US taxes from last year to go back and claim the money that the UK has right to first taxation of as I was UK resident and non-resident in the US. However the double taxation treaty only covers federal income taxes but I also paid California (CA) income taxes. The following page suggests that it is admissable to claim FTRC on California income taxes https://www.gov.uk/hmrc-internal-manuals/double-taxation-relief/dt19851 but there is no way to claim tax relief in the CA tax form so does this mean I can claim the FTRC against the CA income tax on my UK return and then claim the tax credit against the federal income tax on my US return?

Hi ForeignIntern,
Aaccording to DT19851, state taxes are not mentioned as being allowable for California -                                                                                                                                                                                                                                                                                                                                              California
Admissible
Corporation income tax
Personal income tax
Insurance companies tax on marine insurance companies bank and corporation franchise tax.
This tax is charged on a ‘unitary’ or world-wide combined reporting basis.                                                                                                                                                                                                                                                                                                                                                                           Not mentioned, you cannot claim FTCR for state taxes.
Thank you.