Here's how to convert horizontal video to vertical format in Premiere Pro.
Step 1:
Go to Sequence in the top menu and select Auto Reframe Sequence.
Step 2:
In the settings window, find Target Aspect Ratio and select Vertical 9:16.
Step 3:
Click Create to automatically convert your video.
Premiere Pro will intelligently reframe your content to keep important elements in view for mobile viewing. Your video is now perfectly formatted for vertical platforms.