FOSS Linux published a guide about setting up NFS Server on Ubuntu Server.

Setting up NFS Server on Ubuntu Server

Here's how to install and set up NFS Server on Ubuntu so you too can start sharing data with other client systems. We shall show how to set up the host server as well as show you how to set up the client-side. For this tutorial, we will be using Ubuntu 20.04 LTS.

Setting up NFS Server on Ubuntu Server | FOSS Linux