Hi Subhadra,
Currently, we do not have support to fill form fields in Essential JS2 PDF viewer. However, we have plans to provide support to fill form fields in EJ2 PDF Viewer and it will be available from our 2019 Volume 3 release which is expected to be rolled out in the month of October 2019.
Now, you can track the status of your request through below feedback link.
Note: We will provide support to load the existing form fields and allow to fill and save it, but we cannot add the form fields in the UI level of the PDF Viewer.
Regards,
Ramya T