Follow the steps below to get the Access token of Square.
Step 1: Sign in to the Square Developer Portal => https://developer.squareup.com/apps using your Square credentials.
Step 2: Click the + button to create an application (in the dialog box icons, select the options you want).
Step 3: If you were not automatically redirected to the settings page, click the Open button (see image above). On the settings page, notice whether Sandbox or Production is selected (these are two completely different environments). If you are going to migrate your main shop, then you need to select Production.
Step 4: Scroll down and find the Sandbox/Production Access token and click the Show button to show the token itself.
Step 5: Copy the token and paste it into the appropriate field on the MigrationPro connection page.
*Remember that our support team is always ready to help you if you encounter any difficulties during this process. Happy migration!