Adding a repository

Help and Support Help
1

I want to install “build-essential” in Volumio 3. To do so, I need to add a repository.
I tried the command sudo add-apt-repository, but no dice.
Does anyone know if it is possible to add a repository? and if possible what repository would I need to add “build-essential” ? Txs

2

Just

sudo apt update 
sudo apt install build-essentials

I never added a repo for that.

3

Txs Much!. BTW its build-essential just for the next person that needs it.