@kingu I use this way

@kingu What is the form field for the video thumbnail? (do you upload it?)

@miinatsu@sopuli.xyz Here I see the preview

@kingu But works on your instance 👌

@kingu I do not see the preview image here (I do not know if this is a problem only here on my instance) but if you see into the Lemmy (Sopuli) page you have the correct HTML tag:

meta ... property="og:image"

@miinatsu@sopuli.xyz This is a test to see the preview here
https://sopuli.xyz/post/26120782