I can't find Beaver streaming anywhere. I have it on DVD, but at times I like streaming better.

So how does the royalty thing work with streaming? Does Amazon or others have to pay every time we watch a show?

Peacock is subscription.

This should work.
https://therokuchannel.roku.com/details/66cc50e20b9850979362bca326ee4630/leave-it-to-beaver

It's available to stream for free on the Roku Channel.

Some of the episodes that Roku look a wee fuzzy. Just a heads up.