I did 1-time transfer from Roth IRA to HSA. I tx my CONTRIBUTIONS from my Roth (not my EARNINGS). Is this deductible? How do I enter it? (cf https://tinyurl.com/sczr3sq)

It's extremely unusual for someone to do an HFD from a Roth IRA and it's usually unwise to report it as an HFD, so TurboTax does not support reporting it that way.  If the amount distributed from the Roth IRA, including the money transferred to the HSA, was less than the amount of your contributions to the Roth IRA, do not report the money as transferred to the HSA.  Instead, report the regular Roth IRA contribution and report a separate HSA contribution.  If the Roth IRA distribution was not a qualified distribution, TurboTax will calculate the taxable amount of the Roth IRA distribution on Form 8606 Part III (with the result being $0 taxable if it all came from your contributions), and you'll receive an HSA deduction of an equal amount.  If you report it as an HFD under these circumstances, the transfer is still nontaxable but you don't get the deduction.