This page signs transactions with a private key typed directly into it. That's only ever safe when:

• You open this exact file locally (double-click / file://) — never host it on a server or share the file with anyone
• You use a dedicated wallet for minting, not your main wallet — only fund it with what you need for fees + gas
• You never take a screenshot, screen-share, or screen-record while your key is visible
• You close this tab (or hit "Clear key") when you're done — the key lives only in this page's memory and is gone on reload

If "Start" won't respond or stats won't load: some RPC nodes block requests coming from a file:// page. Try serving this file locally instead, e.g. run python3 -m http.server in its folder and open http://localhost:8000.