Hi PakhomCh, welcome to Roll20. Sheets on roll20 are basically created from scratch using html, css, and javascript(with some roll20 restrictions/limitations). You can learn about the details on roll20's wiki: <a href="https://wiki.roll20.net/BCS#Sheet_Structure" rel="nofollow">https://wiki.roll20.net/BCS#Sheet_Structure</a> Also, you'll need to have a pro level subscription to use custom character sheets. Basic sheets can be created with very little coding pedigree. More complexity requires more skill. Many people start by editing/customizing an existing sheet before trying to create one from scratch. Ask questions on the forums as you progress. Goodluck.