Display dialogs from the command-line/shell scripts. Return user-inserted values or 1 if error. More information: https://manned.org/zenity.
zenity --question
zenity --info --text="Hello!"
zenity --forms --add-entry="Name" --add-password="Password" --separator=";"
zenity --file-selection --directory
(echo "#1"; sleep 1; echo "50"; echo "#2"; sleep 1; echo "100") | zenity --progress