how to scroll up in screen code example

Example 1: scroll up in screen

Press "Ctrl-A" on the keyboard and press "Esc."
    Press the "Up" and "Down" arrow keys or the "PgUp" and "PgDn" keys to scroll through previous output.
    Press "Esc" to exit scrollback mode.

Example 2: screen scroll up linux

Ctrl-a [ or Ctrl-a <esc> (also used for viewing scrollback buffer)

https://gist.github.com/lifeeric/4da6652615deefe9640fd683c4170b91