you cannot pull this image, you’ve built this locally and pushed nowhere.
you need to USE the image.
let me copy paste the relevant section:
Use Images
On the compose.yaml replace the image reference to the tag you used when you built it. Then, if you used a tag like custom_erpnext:staging the x-customizable-image section will look like this:
x-customizable-image: &customizable_image
image: custom_erpnext:staging
pull_policy: never
The pull_policy above is optional and prevents docker to try to download the image when that one has been built locally.