I'm trying to do exactly this, but I get an error:

C:\Users\xxx\AppData\Roaming\Bitcoin>"C:\Program Files\Bitcoin\daemon\bitcoin-cli" dumpwallet mpscan
error code: -4
error message:
This type of wallet does not support this command

It was a brand new wallet created with Bitcoin Core yesterday, I think I used the wrong parameters and made a "descriptor" wallet? I don't know.  All I know is that there is a public address in this .dat that has a ton of bitcoin and I can't get it out and don't have the server it came from anymore. Long ass story. lol