Importing Photos AND Captions from Pictures to Photos for many photos together

Hi Terrence - Apologies for not replying sooner.

Anyway, what I have been trying to say - when downloading photos through the Google online photos feature (from an Android), I can add captions whilst the photos are in Download and then when the photos are in Pictures. However, when transferring the photos and the captions, to Photos, the captions are shown in Photos, but in a "grey-out" way that does not allow me to copy the captions

If I then Click on the entire photo and caption to Share to another source (through emails or to Facebook, etc) the caption does not come across. and that has to be added after.

When now in Pictures, I click the "Get Info" feature on the photo, I note the caption does not appear on the "Add A Title", but on the line below, which then does not appear in bold on the Photos page.

My question - when adding a caption in the Pictures or Downloads page, how can I ensure that this caption appears in Photos in such a way that when sharing, the caption follows? And is it possible to do this to all the photos at the same time, not one by one, as I have over 30,000 photos in my Photos Album.