Square integration creates a whole new form

I started a jot form and i'm trying to intergrate square but it's making a whole new form. Instead of adding to existing form. 

If I'm understanding your concern correctly, you are trying to add the Square payment field in your form through this page (https://www.jotform.com/integrations/square) by clicking this button.

That option will open the form builder page for a new form. If you want to add the Square payment field to an existing form, please go to the builder page of the form you would like to add the integration to and refer to my screenshot below.

Reference Guide: How-to-integrate-form-with-Square

Please give it a try and let us know if you need any further assistance.