Copying all the keywords that will export to an external file

Hi all, I really have a stupid problem but I can’t figure out how to do this and was hoping someone might be able to help.

What I trying to do is to copy all of the keywords that will export from a specific image into a text file. Unfortunately, I use a lot of synonyms in my keywords so I can’t just copy the keywords from the enter keyword text box in the Keywording Panel.

What I’ve been doing up to this point is: I will keyword the photo and then export it to my desktop, and after that copy the image into the Photos Application on the mac, right click on the Image and choose Get Info.

This is been working perfectly fine, however, I just found out that not all of the keywords that exist in the Image file show up in the Photos / Get Info / Keywording section.

I originally thought that it might be the file that was the problem but I did a test and the file has all of the keywords but when it’s imported into photos some of the keywords are missing. keywords but when it’s imported into photos some of the keywords are missing.

Is there a plug-in or another way of doing this in Lightroom? any help on this would be greatly appreciated. Thank you in advance, - CES