https://wccftech.com/word-and-powerpoint-for-ipad-now-support-multiple-windows/

Microsoft has released updates for Word and PowerPoint for iPad with support for multiple windows. This lets users open multiple instances of Word and PowerPoint, and even use them in Split View with other apps.

Apple had introduced the capability for apps to create multiple windows with iPadOS 13. All built-in apps in iPadOS allow users to create multiple instances, while third-party apps are still rolling out support for this useful feature.