When I click the cancel button in App creation page, it works like a submit button.

To Reproduce this issue:

Components -> Payplans -> Apps -> My Apps -> Create App Instance -> Click Close button

When I cancel the new form page that appears in 'Create App Instance', instead of cancelling the page and going back, it is showing an error stating "Title field is required". Please find the attachment.

I am using Joomla 3.8.1 with Payplan 3.6.3