Diego! no es difícil, pero tampoco hay buena documentación al respecto. Dejo aquí los pasos que me compartió muy amablemente @Richard of TND, quien le agradezco mucho !!!
1. Go to https://lvllvl.com/c64
2. On the emulator, go to the menu C64 and then attach /run disk (or PRG)
3. Go to the Share menu and select Export/PRG/D64/CRT as HTML
4. Edit the C64 hardware settings (SID, joystick port) then click on DOWNLOAD
5. Rename the .zip file e.g. Tiburoncy_web.zip
6. On itch.io, re-select kind of project, as HTML (The D64 download will still stay on the web site)
7. Upload Tiburoncy_web.zip on to your page and check mark it as this file will be played on the browser
8. Save everything.
Suerte con eso !!! 😉
Saludos