itch.io

Here’s the Unity 6 → itch.io workflow:

1. In Unity, open File → Build Profiles. Select Web, or choose Add Build Profile → Web if it is not listed. If Unity prompts you to install Web support, install it through Unity Hub. Then select Switch Profile. Unity build profile guide
2. Check that your game’s scenes are included in the build. Click Build and Run to test it in a browser. For the version you upload, turn off Development Build and click Build. Unity Web build settings
3. Open the folder Unity built. Zip its contents, so index.html is at the top level of the ZIP alongside the Build and other generated folders. Do not zip the enclosing folder.
4. On itch.io, create or edit your game page, set Kind of Game to HTML Game, and upload the ZIP. Set the embed size or choose fullscreen, then save and preview the page. itch.io HTML game guide