Regarding the Final Project

To submit the final project, do we have to send an email to bolt with a pdf document or can we submit our hackster link?? And is the project video necessary for submission?

The capstone project is to be submitted through a pdf document with photos and screenshots to support@boltiot.com . And for the final project submission for certification exam you will have to enter the link to hackster.io project made by you .
The video is not necassary anywhere whether the capstone project or final project.
I would advice you to make a different and new project for your certification exam. Marks are there for uniqueness of your idea too.