add a live demo url

Is any one know how to solve this problem what should to do
is that mean i must book domin url .
and other question
Is the demo which we upload it to reviewer must include image or placeholder

You need to put your theme to your hosting in order to see it working live.

You can add placeholder images to the main zip when uploading it to CodeGrape.

Is codegrape provides hosting can be purchased

You can zip all files in a folder and upload it to "Preview Source" field.