It seems to need a backend to fetch metadata so as to bypass CORS...
I can try to create my own (in Now.sh), but it wouldn't support multiple media types by default.
Also, this should be done in
dev.to to enhance
<a href>s (currently, only handful stuffs are supported, like GitHub and Dev.to posts).
Interestingly, Dev.to seems to generate
og:image when I post in Discord.