https://wccftech.com/download-now-apple-releases-ios-15-and-ipados-15-beta-6/

You can download and install iOS 15 and iPadOS 15 beta 6 today for your iPhone and iPad. The update is available for developers only.

For full tutorials on how to download and install iOS 15 and iPadOS 15 from scratch, then make sure you check out the following: