file-pdf-save-multi requires an array of image ids and it seems you don't have it (your #comment I did strike shows you tried though)
images = gimp.image_list()
# num_images, image_ids = pdb.gimp_image_list()
pdb.file_pdf_save_multi(len(images), images, False, False, False, filename, filename)
you should have something alike
images = gimp.image_list()
images_ids = [img.ID for img in images]
pdb.file_pdf_save_multi(len(images), images_ids, False, False, False, filename, filename)
https://www.gimpusers.com/forums/gimp-us...save-multi
there is also an interesting discussion there ➤ http://gimpchat.com/viewtopic.php?f=9&t=12418
images = gimp.image_list()
pdb.file_pdf_save_multi(len(images), images, False, False, False, filename, filename)
you should have something alike
images = gimp.image_list()
images_ids = [img.ID for img in images]
pdb.file_pdf_save_multi(len(images), images_ids, False, False, False, filename, filename)
https://www.gimpusers.com/forums/gimp-us...save-multi
there is also an interesting discussion there ➤ http://gimpchat.com/viewtopic.php?f=9&t=12418