It always said that I didn't support WebGL, I don't understand!

I think this is just an internet error that happens from being idle for too long.

what browser are you using

please go here to see if your browser supports webgl, if it doesn't, click on the globe icon above the new reply text box:

Output wrote:

My browser / operating system: Windows NT 10.0, Firefox 100.0, Flash 32.0 (release 0)

so we can understand the situation better.

or you can use this get.webgl.org theres tutorial if your webgl isnt enabled