I once was able to customize the thumbnail and message for my Blogger page whenever it was shared via text message, Facebook Messenger, Facebook Post, etc., by using an open graph generator.

I'm going to show you how to do it with a Xara website.

1. Go to https://smallseotools.com/open-graph-generator/

2. Enter your information, then copy your generated code

3. In Xara, go to Utilities>Web Properties>"Website" Tab>"HTML Code (head)" Button: then paste it into the dialog box after you click the button
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4. Click "OK" then "Apply"

5. Re-publish the website with your new code.

6. Go to https://developers.facebook.com/tools/debug/ to clear Facebook's cache of your old preview, just enter your site's URL and click "Debug".
The new preview won't apply on Facebook unless you do this, but it seems to work just fine with every other service I've tried. (I'd do it anyway . . .)

7. Test your new site preview: share it on Facebook messenger, WhatsApp, text message or whatever service you commonly use.

This is my result:
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Peace be with you,

Braden.