I want to know , where I have to post the video of my project og LDR??
You dont have to post videos that are in the course module.
But in case you are asking about the Final Project for submission, You have first create a new project on projectsubmission.boltiot.com/ , make the necessary steps you performed to build the project, Upload the video on youtube, then add the embed URL (from share button on youtube video) to the created project document.
Update - The site is currently down. You will be informed once they have fixed it.
Now the site is working you can proceed with your submission