The DeroGold wallet syncs the chain on WebAssembly threads, which browsers only allow on a cross-origin isolated page. The server hosting this page is not sending the two headers that grant it:
Cross-Origin-Opener-Policy: same-origin Cross-Origin-Embedder-Policy: require-corp
Add them and reload — the wallet will not start without them. See
README.md in extras/web-wallet for a worked
nginx configuration.