Access phpunit inside my project folder. phpunit: command not found

I have installed phpunit by opening gitbash of my windows system and running the following command.

composer require --dev phpunit/phpunit ^9

It installed successfully and when I type following command

./vendor/bin/phpunit --version

it returns PHPUnit 9.5.21 . I think phpunit is installed in this location

C:\Users\ERIKSON\vendor\phpunit

Now I have a project in my xampp folder

C:\xampp\htdocs\erikson-project\wp-content\plugins\youtube-plugin

when I open GitBash in this project location and run the command PHPUnit it says

bash: phpunit: command not found

. How can I solve this ? Please help.

I have composer.json file inside youtube-plugin folder and the code is C:\xampp\htdocs\erikson-project\wp-content\plugins\youtube-plugin\composer.json

{
    "require-dev": {
        "phpunit/phpunit": "9.5"
    }
}

Do I need to add anything in my windows system environment variable?