the error says the installer does not find the „pip“ command line tool. This should automatically be installed by the installer itself, but sometimes fails due to problems with official Raspbian download servers.
What you may try:
– install again and see if the error occurs again
– still showing the error? Then install pip via command line (use SSH to connect to your Pi) and install with „apt-get update && apt-get install python-pip“
– this time the installer should succeed