My domain is hosted with a popular domain name company, whos name I won't mention. Then my website is hosted by a hosting provider.
Yet, for some reason the domain name company, only allows the Meta Description and Meta Keyword tag in URL Frames.
That leaves me with the following problem, I can't put the following code in the URL Frame (or Iframe):
<meta property="og:image" content="url of thumbnail"/>
This is needed for Facebook to pick up the thumbnail when being posted.
Is there any way I can achieve this without switching domain hosting?
.Htaccess maybe?
Your problem is one of many issues with using frames.
Search engines and other services (like Facebook) can’t work with your domain, as it always points to a different resource (everyone would always be lead to the home page of your site when following the link).
You could use the "real" URL of your page (i.e., of the frame), which is probably the one provided by your hosting provider.
Right click on your page, the context menu should show something like "Load this frame only". That’s the URL of your page. For images, a right click on the image and something like "Copy image URL".
You should definitely switch to a hosting/domain provider that allows you to use the full power of your domain.