Multilayered PSD from a list of images using #Gimp

layers-to-psd.scm

;; Copy to ~/Library/Application\ Support/GIMP/2.10/scripts/
;; Ref. https://stackoverflow.com/a/24164916/1765629
;; Usage example: 
;;   gimp -i -b '(layers-to-psd (list "Background.jpg" "A.png" "B.png") "compo.psd")' -b '(gimp-quit 0)'
;;
(define (layers-to-psd image-paths psd-path)
  (define (add-layers image image-paths)
    (when (not (null? image-paths))
      (let*
        (
          (img-path (car image-paths))
          (layer (car (gimp-file-load-layer RUN-NONINTERACTIVE image img-path)))
        )
        ;; (display img-path) (newline)
        (gimp-image-insert-layer image layer 0 -1)
        (add-layers image (cdr image-paths))
      )
    )
  )
  (let* 
    (
      (base-path (car image-paths))
      (image (car (gimp-file-load RUN-NONINTERACTIVE base-path base-path)))
      (drawable (car (gimp-image-get-active-layer image)))
    )
    ;; (display base-path) (newline)
    (add-layers image (cdr image-paths))
    ;; LZW compression (1), MSB to LSB fill order (0)
    (file-psd-save RUN-NONINTERACTIVE image drawable psd-path psd-path 1 0)
    (gimp-image-delete image)
  )
)

Do you get any error messages? I can't help you without any information. Although even if I had the info, I'm not very familiar with GIMP. You better post a question in Stack Overflow.