Fix 'Yarn not installed' Error: Installation Guide

To resolve the 'Yarn not installed' error, you need to install Yarn on your system. Here are the steps to install Yarn:

1. Open your terminal or command prompt.

2. Check if you have Node.js installed by running the command node -v. If not, you need to install Node.js first.

3. Once Node.js is installed, run the following command to install Yarn globally:

npm install -g yarn

This command will install Yarn globally on your system.

4. After the installation is complete, verify if Yarn is installed correctly by running the command `yarn -v`. It should display the version of Yarn installed.

Now, you should be able to use Yarn for your project without encountering the 'Yarn not installed' error.