Zsh: command not found: yarn

I am trying to do the yarn command to be able to start the NFT marketplace but I am getting the error zsh: command not found: yarn as shown in the picture. Does anyone know what I am doing wrong or why this error is occuring? I appreciate any assistance.

Probably because you haven’t installed Yarn in your system yet. If you have Node on your system you can install yarn with

npm i -g yarn