https://wccftech.com/download-macos-big-sur-11-3-beta-7-now-available/

Apple has seeded beta 7 of macOS Big Sur 11.3 to registered developers. The update is available over the air right now.

Apple released the seventh beta of iOS 14.5, iPadOS 14.5 beta 7 and others yesterday, and today the company is making more strides by releasing beta 7 of macOS Big Sur 11.3.