In Keys you can specify 1 key in the left column and a timestamp in the right column. Pressing that key will play the video from the specified timestamp. Warning - if you are focused on the video your keybinds will not work. Click somewhere else on the page to focus away from it. There is no workaround for this, unfortunately.

In Auto play you can specify an order of timestamps to automatically play a song. In the left column specify the start timestamp and in the right - the end timestamp. When clicking Play in that menu the video will be played in order from the timestamps from top to bottom, for each row playing from the left timestamp to the right timestamp. Specifying timestamps out of the range of the video will result in the video being paused for the duration between the two timestamps. This way you can create automatic songs from YouTube videos. Pressing Record will record they keys clicked and fill in the auto play tab for you. Click Share to share the song as a link with a friend

In the field above the video you can paste a link to use a different video. Enjoy.