Google is a pain. I use
https://ctrlq.org/google/photos/
To create a sharable link to the photo.
This works well on a phone as well, I rarely view TL on a pc.
On the photo in Google click "share", then "share a link"
Paste that link into the crtlq.com page and copy the resulting direct link into the TL "insert image" box.
It's easier than I make it sound but still not great if doing dozens of pictures.
I should be able use the subscribing members direct upload facility but never worked out how to do it on a phone.