NFS does not use any type of authentication or encryption. You should only use it over a trusted lan or with a vpn such as wireguard.

Install

void linux

https://docs.voidlinux.org/config/network-filesystems.html

alpine linux

doas apk add nfs-utils

/etc/exports

The file /etc/exports contains a table of local physical file systems on an NFS server that are accessible to NFS clients. Each line contains an export point and a whitespace-separated list of clients allowed to mount the file system at that point. Each listed client may be immediately followed by a parenthesized, comma-separated list of export options for that client. No whitespace is permitted between a client and its option list.