If you can find a holder on its own, or you can easily remove the lens from the holder you should be able to get a good optician to have a lens made to your prescription to fit into the holder.
I considered doing this for my Leicas many years ago, but didn't go through with it as my prprescription had too much astigmatism to be practical.
I purchased diopters for my XPro-1 in 2021 from a shop named Downtown Camera. They are in Canada. Initially, they didin't want to ship to the US. I asked them (nicely) to see what the shipping charge was and that I'd cover it. To get two diopters shipped, it was $65. Links to the diopters on their web site are below.
I have now idea if they're still around and if they'd ship but it'd be worth a try.
