how can i know how the id is generate in background slide of course presentation

hello;

i have à course in power point (300 pages) so i want to import it in h5P course presentation ,i found this solution:

1.import my power point  in images

2.in moodle i create course presentation then i add image by image as background slide

this solution it's not very usefull and i want to find another method (if some one know i will be gratefull )

3.for me the solution found it's to upload the h5P after creation in moodle plateform and in content file in images i copy paste all my images (the images of powerpoint)

but the problem in h5P course presentation when we add backgound slide there is id with it (imageSlideBackground-607d823d961cb.jpg)

and i don't know how can i added this is ???