Here are the steps to add Button in command bar.
STEp:1 Open Ribbon Workbench
STEp:2 Select the Entity for Editing
STEp:3 Drag a Button to Command Bar
STEp:4 Modify the values according to your need.
STEp:5 Add a Command of Type URl Action
STEp:6 Associate the command in Button section
STEp:7 – Now Click on Publish and Confirm
STEp:8 – Wait for the Publish Success
STEp:9 – Goto Account Record and Check the Button on Account Form Command
STEP :10 Open an account to check if the button is visible and the Google link opens up.
Thanks for reading the tutorial hope this helped.