This is an Unity issue, not an Itch.io issue. Perhaps you could help on the Unity forums .
https://forum.unity.com/threads/solved-webgl-build-error-unable-to-parse-build-file-name-framework-js-br.1102759/#:~:text=HTTP%20response%20header%20when%20serving%20the%20files%20with,Unity%20embeds%20a%20Brotli%20decompressor%20into%20the%20build.
