nixCraft published a quick tutorial about creating a Sudo user on Ubuntu Linux 20.04 LTS.

Create Sudo User on Ubuntu 20.04 LTS Linux Server - nixCraft

A step-by-step guide that shows you how to create a new user or add an existing user with sudo access on Ubuntu 20.04 LTS Linux server.

Create Sudo User on Ubuntu 20.04 LTS Linux Server - nixCraft