This build needs a cross-origin isolated page and the server is not sending the required headers, so it may fail to start. See the README section on COOP/COEP.

The build did not load. Most often the server is not sending Cross-Origin-Embedder-Policy for this folder — open the build directly to see what the server actually returns. Setting GAME_FRAME_VIA_PHP to true in config.php works around it.