Your browser is drawing with the CPU instead of the GPU, which usually means hardware acceleration is turned off. malmal will run, but it will be slow. Turn hardware acceleration back on in your browser settings, or use the desktop app.
WebGPU isn't available in your browser, so malmal falls back to WebGL. It will run, but more slowly, and some features may not work correctly. Updating your browser usually enables WebGPU. Or use the desktop app.