Need to use enable existing pdf fields

Hi @babaiah, welcome to the Docusign Community! This is definitely doable. Here’s our support page on how you can define your PDF Form fields so that they can get converted to Docusign tabs when an envelope is created - https://developers.docusign.com/docs/esign-rest-api/esign101/concepts/tabs/pdf-transform/

Take a look at this article, especially the naming convention for the PDF Form fields as without those, we won’t be able to convert the fields into tabs properly. Let me know if you’re having any issues.  

Is it possible to enable only particular page or section fields instead of entire pdf fields? and checkbox functionality is not working properly it is allowing to select both options for questions.

No, form field conversion is done on the entire document and can’t be separated by page or section. 

Re: checkboxes, this would need testing but I’m fairly certain that the checkbox behaviour can be redefined in the API call by following what’s mentioned here: https://www.docusign.com/blog/developers/tabs-deep-dive-checkboxes-and-radio-groups

You’d just need to define a checkbox group, the rules for the checkbox group. When you define the checkboxes, make sure their data label parameter matches the Adobe PDF form field name, so that we don’t create duplicate tabs, instead just adapt the ruleset for those form fields. 

If you’re looking to convert only specific tags or tags in specific locations, I would instead recommend anchor tagging: https://developers.docusign.com/docs/esign-rest-api/esign101/concepts/tabs/auto-place/