most relays on ddsrs and alienos relay:
https://github.com/dezh-tech/alienos
are supporting nip-86. if you run them, you can use it.
about nip86 client, we have nak:
gui client? we don't have any. i had a project called mangostr:
https://github.com/dezh-tech/mangostr
but i don't have enough time to work on it and i wasn't able to receive a grant for it so i put incentives for more devs. then it's abandoned at least for now.
you may want to develop yours. 🫡