https://wccftech.com/download-ios-14-beta-3-without-developer-account-for-free/

Here's how you can download and install iOS 14 beta / iPadOS 14 beta 3 without a developer account, absolutely free, on your iPhone or iPad.

Registered developers can go ahead and download iOS 14 beta 3 and iPadOS 14 beta 3 updates over the air immediately. There's a high chance that you want in on the action, but beta software from Apple isn't free as it involves enrolling in the developer program, costing $99 on an annual basis. That is not entirely true, as the company has an official Beta Software Program, which is absolutely free, and using the program, you can test drive upcoming software absolutely free. The only downside to the Beta Software Program is that developers get the update before anyone else, with the public beta arriving after a short while. It's not a bad deal at all, since it's absolutely free. If you are all up for it, then you can find more details here: Apple Releases iOS 14 and iPadOS 14 Public Beta - Here's How to Download