Well that depends upon whether you are using your own Raspberry Pi or the XRange device?
If you are unfortunate enough to be using the XRange then I believe you could be out of luck as AirNav bundle their own mlat-client within their rbfeeder package and you will have no access to your own device to do anything at all.
If you are lucky enough to have your own Raspberry Pi and it is running Buster then this is what worked for me. This assumes you already have a working system of course;
First download & install the recompiled mlat-client from the Github of abcd567 who is a trusted source;
wget
https://github.com/abcd567a/mlat-client-package/releases/download/v1/mlat-client_0.2.11_BUSTER_armhf.debsudo dpkg -i mlat-client_0.2.11_BUSTER_armhf.deb
Then to prevent this being overwritten by the AirNav version every time you update your packages by the usual sudo apt update followed by sudo apt full-upgrade you would type;
sudo apt-mark hold mlat-client
This literally puts a hold on the mlat-client from adcd567 so it doesn't get updated.
I would think the man himself will be along before long to offer his advice and/or correct me if I am wrong as its been a while since I went through this procedure myself.
Hope that helps?
Kind regards,
-=Glyn=-