This is a tricky one.
First of all, head to this url provided by Facebook which is a tool where you see a lot of information regarding the images.
https://developers.facebook.com/tools/debug/og/object/.
There, type for example this url: https://incvice.com/head-first-programming-python-coffe-beans-html-page/.
Now click on “fetch new scrape information”.
You will see at some point the tag: “og:image”.
You need to specify an og:image tag in the
of your web page.An example:
1 2 | <meta property="og:image" content="https://incvice.com/wp-content/uploads/2016/01/ head-first-python-coffe-beans.jpg" /> |
Put the same tag on your website. This should fix your issue.
You can do some tweaks in php if your images are unique and dynamic. Or just set a standard image.
For the og:image tag, the content values must not contain blank spaces, use %20 instead.
Also, you need to provide the full url, including http:// etc.
If you have questions, leave in the comments.