In Vim, insert some text into a file, such as date.
In insert mode, press !! to switch to command mode and see a :.! prompt.
Enter a command, like bash to execute on the given text.
The text is replaced with the result from the command - Sat Jul 12 23:16:29 BST 2025.
This also works for other commands, such as typing 1+2+3 and running :.!bc will return 6.