Instructions
Set up a Redirect URL and Notification URL on your application
Configure Square Terminal in the Backend
Set up Pusher Sockets
...
1. Set up a Redirect URL and Notification URL on your application
Before configuring Square Terminal in the Backend, you need to set up a Redirect URL and Notification URL on your application.
Redirect URL
The redirect URL is the endpoint for your application or web page that processes the seller authorization response and manages the seller’s OAuth tokens. You need to add this URL to your application using the Developer Dashboard.
To set up the redirect URL, go to the Developer Dashboard, choose Open for your application, in the left pane, choose OAuth. In the Redirect URL box, enter the URL that redirects the seller authorization to your application, then choose Save (or you can get the redirect URL quickly by copying the redirect URL that is auto-generated by your domain into the Guide section of Square Terminal in the Backend page, then paste it to the Redirect URL box.
Notification URL
Applications need at least one reachable notification URL to receive and process webhook events from Square. Notification URLs are specified on the Webhooks page of your application in the Developer Dashboard.
...
composer require "square/square:*13.1.0.20210818"
via your sshbefore you connect with Square.
...