I am in design and I need to take a screenshot of my company's app that already exists to match the UI for marketing. How do I take a screenshot? I tried developer mode but it seems like you can't screenshot an app if it's already in existence as opposed to being worked on.
You might get a better response within the Developers area of this forum (you're on the user side, not the Developers). But when I need a screenshot I simply use my phone camera. I realize it's not as screen perfect as a screenshot, but it's quick and easy.
There is no support for doing that in Roku OS. As @rdm96 suggested, you can take a picture of your screen with a camera. You may also be able to use a HDMI capture device connected to the output of a Roku set-top box. I've used a model like this one on Amazon before.
@rdm96, you can only take a screenshot of a sideloaded channel/app.