How to make Outlook web app to display the subject as the title of the email?

Step 1: Sign into https://portal.office.com/

Step 2: Navigate to Outlook web app or access https://outlook.office365.com/

Step 3: Click on the settings gear icon on the top-right corener of the page and select View all Outlook settings.

Step 4: Switch to Mail > Layout tab and scroll down to Message list format section.

Step 5: Select Subject first and click Save.