As the connection will be an application that interfaces with Square, you will need a Personal Access Token to access the Square server. To obtain a personal access token, you need to create an application at Square as a developer, go to the Square credentials page, and retrieve the Square personal access token. This can be done with a free Square account.
At the Square website:
Create an application by clicking the plus in the Applications box:
Give your application a name and then click the Create Application button:
The Applications screen will then be displayed.
Select your application and click Open:
Personal Access Token¶
The Personal Access Token will then be displayed in the Sandbox Access Token or Production Access Token text box. Copy it and store it safely where you can retrieve it when configuring the connector: