In this context, you are going to know how to take scrolling screenshots, so read this post till the very end.
Simply take a screenshot and wait to get the screenshot toolbar
Now, tap on Capture more option and it will take a screenshot of the whole page
But this feature is only available in android 12 mobile phones, if you have an older version phone then, you need to take help from a third-party website or app.
Read More: https://getassist.net/does-facebook-notify-screenshots/