HELP! Changing Website Preview Thumbnail

Hello, I’m trying to change the website preview thumbnail image with the meta tag:

The problem is that whenever I test, the image is a JPG screenshot preview of the actual project (top viewport).

I’ve tried to override the screenshot JPG with the image (above) but it splits the thumbnail into 2 separate images: ONE with the screenshot (Left side) and the THE OTHER with my custom image I’m referring to (Right side).

Someone please help!! haha thank you

Thank you to Hugo for helping me out!