thanks, that worked a treat!
If we wanted to upload an image on that same page (admin/customize/themes/2) I presume we could edit the head section via “edit HTML/CSS”? If so, what would that line look like instead of
<meta property="og:image" content="https://cdck-file-uploads-global.s3.dualstack.us-west-2.amazonaws.com/standard10/uploads/[ourcompany]/original/1X/[rendomfilename.png]">?