As streaming device experts, we've detailed how to capture screenshots on Android TV in our recent guide: How to Take Screenshots on Android TV. Yet, among popular set-top boxes, Roku stands out as one of the trickiest for screenshots—many articles resort to generic TV photos because direct captures are so challenging.
That said, it's not impossible on Roku. The process requires enabling developer mode, but with our tested steps below, you'll get pro results reliably.

Follow these precise steps on your Roku remote and computer for success. We've verified this on multiple Roku models.
Important Note: This method works only for installed apps. Search online for .zip installer files for popular apps to sideload them first. Always use trusted sources to maintain device security.