@Opus 17
If I understand correctly, while an HSA contribution for 2021 can be made until April 15, 2022, any distribution from the HSA has to be reported in the year it is actually made. You can't take a distribution in 2022 and designate it as a 2021 distribution. Am I right about that?
So @georgiabulldogs111 can report the 2021 HSA contribution, and get the deduction for it, on her 2021 tax return. And she can reimburse herself from the HSA in 2022 for an expense she paid in 2021, but it will be a 2022 distribution. It will be on her 1099-SA for 2022, not her 2021 1099-SA, and she will have to report the distribution on her 2022 tax return, not her 2021 tax return. As long as she used the distribution for qualified medical expenses, it will not affect her 2022 tax, but she will have to report it on her 2022 tax return because it will be on her 2022 1099-SA.
