PowerApps Control Framework (PCF) is a framework that helps programmers to make custom control and use it in a Dynamics CRM environment. Even though the framework still in the preview stage and might be changed in the future, I couldn’t help myself to try this.
The control that I made is a control that got an input file and one save button. Once you choose the image and click Save. It will convert the image into Base64 String and will update the content into the attribute that binds it.

Shout out to all these links that helps me understand PCF better:
You can check my custom control in my github repository.