This article explains how to set up a customer level token variable in Syncro RMM.
To set up site-level deployment tokens in Syncro, you first need to create a Custom Field at the customer level.
To do this, click on the customer you'd like to edit, and in the top right click the "Edit" button. 
From there you'll click the Custom Fields tab at the top, then click "Manage Custom Fields".
Now you'll click New Field and give the field a name such as Zorus Token and the Field Type should be Text Field.
Now if you navigate back to the Custom Fields page for that customer, you should be able to enter the token value in that field and Save Changes.
Next, you'll want to go ahead and import our script from the Community Script Library.
Once imported, on the editable version of the script, you'll want to change the Token "Variable Type" from "runtime" to "platform" and then select the "customer_custom_field_zorus_token..." value to use the populated value for each customer.
Once you've done that, you can update the script at the bottom and proceed with deployment.