Hello Rafsun,
My issue is same, I have created a form with the option to upload featured image.
When I use that form on the frontend, the upload button won’t work.
I follow your above step and uploaded the image from backend and I have the meta key.
But where and how we use that key.
Using meta key I am able to print the image, but I want the upload image button to work and a user can upload an image