There are a bunch of ways to solve this issue. I think the best idea is to use the built-in “Screenshot” function in Unreal Engine, which can be called using a Blueprint or C++.
Here’s a general overview of the steps you’ll need to take:
Create a button that the user can click to trigger the screenshot. This can be done by creating a button widget in UMG and adding an OnClicked event to it.
In the OnClicked event, use the “Screenshot” function to take a screenshot of the current frame. This function takes a few parameters, such as the filename and the resolution.
To save the screenshot to the user’s device, you now will need to implement a solution through your web-server using JavaScript and perhaps PHP (or relevant framework). Simply locate the file saved on the server and prompt the user with the ability to save the image.
The other alternative is to save the image to the users clipboard. I believe you will need a platform OS specific solution. Different platforms copy information to the clipboard differently.