can't mount

[Selenium39]

i create a docker container as a nfs server and expose 2049 port in computer A(ip:172.25.78.130).

docker run -d --name nfs --privileged -v /home/nfs:/data/nfs -e SHARED_DIRECTORY=/data/nfs -p 2049:2049 itsthenetwork/nfs-server-alpine:latest

but i use another computer B(ip:172.25.78.39) to mount it .it's wrong

showmount -e 172.25.78.130
RPC: Remote system errorRPC: Port mapper failure - RPC: Timed out.

[denogio]

This is solely nfs4, so showmount wont work.