First i hope you have the IPTC (and/or EXIF) data available.
If you have the box checked in
Photo ALbums -> Settings -> Basic settings -> General -> I -> Item 9: Enable IPTC before you uploaded, you have it.
If you have it available, look at
Photo ALbums -> Settings -> Advanced settings -> IPTC -> I.
Here you see e.g. under (IPTC) Tag: 2#005, and under Description Graphic name:
The 2#005 is what we call in wppa the IPTC keyword.
If you enter this (2#005) in the description of a photo, See
Photo Albums -> Albums -> <Any album> -> Show photo Detals (of any photo) it will show up at the frontend in the description (e.g. in a slideshow) replaced by its actual value.
You can also use a keyword for the description, in this example for 2#005 you use 2#L005 (the L stands for Label).
If you do not like the description ‘Graphic name:’ you can edit it on the IPTC settings page.
If you want it to happen in all items (if the data is not available you will see nothing, no label and no value), you can set the description for all items in Advanced settings -> New -> I -> Item 13: New photo desc, enable it in Item 12: Apply Newphoto desc (for fuiture uploads), and if you want to apply it to all existing items, run Advanced settings -> Maintenance -> II -> Item 6: Apply New Photodesc.
If you do not have the IPTC data, (if the Advanced settings -> IPTC table is empty), ask me for more instructions to recover.
See also: https://wppa.nl/docs-by-subject/iptc-and-exif-data/