Step 1: Sign into Outlook webmail via https://outlook.com.
Step 2: Click sign-in button on the top-right corner and sign in with your username and password.
Step 3: Click on the Settings gear icon on the top-right and scroll down and click view all Outlook settings.
Step 4: Switch to Calendar tab and navigate to Accounts.
Step 5: Click on Google.
Step 6: Log into your Google account and grant permissions from the pop-up window.
Step 7: Your busy events will be shown in Outlook calendar now.