Customizing Header Button Font

Hi there, I looked at similar (or even almost identical) posts throughout and tried the solutions but I haven't made it work quite for my page.

I've been able to change the header button typeface, but it remains on uppercase. I would like it to be on sentence case.

My goal is for the header button to match the primary buttons, which are set to the following:

Password to site is forestcrystals

Thank you very much!

🙂