Any way to install on arm64 ?

No. The only builds for Windows or Linux are x86 (32bit) and x86_64 (64bit).

You can try using something like qemu to run Fopnu but the performance would probably be really bad. I haven't tried this myself.

https://qemu.readthedocs.io/en/latest/user/main.html

https://wiki.debian.org/QemuUserEmulation

https://github.com/ptitSeb/box64/