Screen Capture vidéo in ligtroom ecosystem

I took photos on a camera that was lent to me and that I didn't know.
On the device, it showed me still images, several, which formed one.
Once placed on the computer, my photos are videos.
I would like to find the photos.

If that's not possible, I have to use the software to select the image I want to keep in the video but I can't figure out how to do it.
I found the instructions for ligtroom classic but not pohr ligtroom ecosystem.

How to do ?