My 2019 macbook pro will not let me redownload mac os from the recovery screen.

Please direct your attention to How to reinstall macOS - Apple Support.

Under Other macOS installation options, you will find a number of different key chords to start your Mac in Recovery. I recommend the following choice:

• On an Intel-based Mac, if you use Shift-Option-Command-R during startup, you might be offered the macOS that came with your Mac, or the closest version still available. 

That is the correct option to use if you want to revert your Mac to its original, "out of the box" condition, so try it. If you still encounter a message similar to the following, be advised it may be a system-wide problem that Apple needs to address:

If so there have been several reports substantially identical to yours, and only Apple will be able to fix it.

Try booting into Internet Recovery Mode using Command + Option + R to see if you can access the macOS 13.x online installer.

Do you have access to another Mac from 2012 to 2023? If so, then you can create a bootable macOS USB installer.

To create a bootable macOS USB installer for:

10.15 you generally need a Mac from 2012 to 2019

13.x you generally need a Mac from 2015 to 2023

Create a bootable installer for macOS - Apple Support

That is the first part of a longer, more convoluted message:

"unable to contact the recovery server...

No response to the request for the version of MacOS you requested using the supplied Apple-ID 'null'.

You erased your Apple-ID. this Mac is now eligible for the original, "shipped in the box" version of MacOS ONLY.