1. Download files from here and upload it to /var/www/pterodactyl

2. Run these commands:

curl -sL [URL]https://deb.nodesource.com/setup_16.x[/URL] | sudo -E bash -

apt install -y nodejs

npm i -g yarn

cd /var/www/pterodactyl

yarn

3. Run the installer:

php artisan billing:install stable

When it asks you for license type wemx.xyz and press enter

4. When installation its over type:

yarn build:production

After that refresh the page and you should have the newest pterodactyl billing for free