Import png files and convert to animation(.mp4) in R

I'm trying to create a short animation with several png files in R. I tried package magick but it only works when I save them to .gif. When I tried to save as .mp4, it will generate an .mp4 file but once you open it, only the first image will be shown.

My code is

  library(magick)
  productPath <- ('/Users/abc/Desktop/products/')
  list <- list.files(productPath, '*.png')
  imagesPath <- paste0(productPath, list)
  images <- image_read(imagesPath)
  animation <- image_animate(images, fps = 20, loop = 1)
  image_write(animation, paste0(productPath, 'test.mp4'))

I found there is also a package called animation, but I don't really know how to import png files with that package. Any solutions? With either package should be fine. Thank you!

You can do like this (assuming the images are in the current directory):

library(animation)
imgs <- list.files(pattern="*.png")
saveVideo({
  for(img in imgs){
    im <- magick::image_read(img)
    plot(as.raster(im))
  }  
})

By default this create animation.mp4.