MacRumors published a story that Apple has released the first betas of iOS 15.1 and iPadOS 15.1 to registered developers.

Apple Seeds First Betas of iOS 15.1 and iPadOS 15.1 to Developers

Apple today seeded the first beta of an upcoming iOS 15.1 update to developers just a day after releasing iOS 15 to the public.

iOS 15.1 can be downloaded through the Apple Developer Center or over the air after the proper profile has been installed on an iPhone or iPad.

  Apple Seeds First Betas of iOS 15.1 and iPadOS 15.1 to Developers