How to cancel a clients subscription order on my weebly website?
Firstly, welcome to the Seller Community! 💫
If you are referring to subscriptions paid for using Square Online Checkout links, you can cancel their subscription for them by heading to this page of your Square Dashboard (Dashboard > Online Checkout > Subscriptions). Once here, select the subscription needing to be cancelled, and click Cancel subscription:

Customers can also cancel their subscriptions themselves from any of the automated emailed invoices they will receive after a scheduled payment. They will receive a confirmation email once the subscription is cancelled, @Cevans.
I hope this helps, but let me know if you have questions about this!
Square Community