Readers of another topic here will guess a lot screenshotting has been going on to capture incriminating data before it got removed. Not everybody knows how. Here are some suggestions for a laptop/desktop computer.
1. Simply hitting the PrtSc button (top right on most keyboards) will capture what is visible on the screen. Depending on your OS it may bring up an application to handle it or put it on the clipboard for pasting into some app elsewhere. Very messy and not recommended but if you see something and you don't have time to do it properly - HIT IT!
2. Add the Vivaldi browser to your computer https://vivaldi.com/. This has a tiny camera icon at the bottom. Click on that and the whole contents of the page your browser has loaded (not just the bit visible on screen) can be dumped to a jpg file.
3. Chrome has an extension that does a similar thing.
For your phone:
* Android: https://support.google.com/android/answer/9075928?hl=en
* Apple: https://support.apple.com/en-us/HT200289
Stuart