This error is what I see all the time now on graphene pixel with amber connected with tor.
This looks outdated and has some things like nip 5 login that almost no one uses
I tried to make an example with NDK recently, the code is very bad but I think you will be able to get the basics of how the remote login works
https://github.com/greenart7c3/ndk-bunker-example/blob/main/src%2Fapp%2Fpage.tsx
Discussion
That relay is apparently not so reliable.
https://github.com/CodyTseng/jumble/pull/417
But I don't think Amber works remotely, when you use Tor.