When a user uses Incognito mode to browse websites, Chrome does not save browsing data and other activities, including websites, searches, and so forth. You won't be allowed to capture a screenshot in Chrome of the Incognito tab. On your mobile screen, Chrome will display the following warning message:
Can’t take screenshot due to security policy
1. Open the app and type "chrome://flags" in the address bar and press on Go.
2. Now in the search bar type screenshot.
3. Under "Incognito Screenshot". Tap the drop-down box and select the option "Enabled" from the list.
4. You'll be asked by Chrome to restart your browser. Click on the "Relaunch" button to relaunch Google Chrome.
5. That's it.