Is there a best way to get a count of all documents/task etc . Like is there a URL endpoint we can just call that's like documents/count?

Hi, I have a Sugarcrm 7.6 pro installation and I want to add a custom button to the Quotes record views and I found this guide in the documentation https://support.sugarcrm.com/Documentation/Sugar_Developer/Sugar_Developer_Guide_7.6/UI_Model/Views/Examples…