This one is not a big problem. Firstly You need to creative Gig. after the make your gig , Fiverr Giving to chance attach some creative gig imagers and One Video to show yout clients. That is the basic concept. The best size of the Fiverr thumbnail image is 550 pixels by 370 pixels. The ideal size for a Fiverr gig thumbnail is 1000×1000 pixels, although the minimum size is 640×640 pixels. Your thumbnail image should be clear and easy to see, with a simple background. check those. Your video is up to 75 seconds and 50mb.
After get an order from the clients and when you submit final you can to attach your image or video file to your gig aslo. fiverr give this chance. watch your right hand its show how to set it. say to your client also accpect that fre promotion. 🥰 Good luck🏆