Fillable PDF with ability for user to add Images

[Trudy16E5]

I am newer here. What I want:

For people using a fillable PDF to be able to add their own image. I have added all the image placeholders using Prepare Form but when I test it as a user in a PDF reader, I cannot add images, though the field is present. 

Suggestions for how to allow this for the user are welcomed!

[Bernd Alheit]

Use Acrobat Reader DC.