While I don’t know anything about this module, a look at the CC1101 data sheet
on page 59 gives the internal register settings needed for 10dbm power output. Presumably you can figure out how to set that value in the library you you are using. I expect you would be better off posting in a wireless (preferably an Ebyte specific forum) rather than here as you will probably get a more informed answer (hopefully by someone that has done it.)
Then you need to find the data sheet for the new version of the cc1101. It should have the commands to enable 20dbm. From this data sheet (found by a google search for “cc1101 20dbm”
you apparently have an additional CC1190 chip to get the 20dbm. It is possible (although the Ebyte docs don’t list it as being present) that it works automatically (that appears correct from the data sheet for the cc1190.) You likely need to determine if the Ebyte module you have includes a cc1190 in which case it should already have a 20dbm output without any modifications.
Looks like this doesn’t apply. The CC1190 is only 915Mhz not 433 … It is unclear how you achieve 20dbm on the E07-433M20S although it seems to claim it is possible. An ebyte forum is likely your best bet.