You need to differentiate between update and upgrade.
You can update maps and firmware - lots of Russian guys have done the hacks. Your unit is probably mmi 3g basic.
To update you can use the link above or Google mmi 3g basic map update.
There is info on DIY here
https://www.a5oc.com/threads/mmi-3g-basic-navigation-5-31-2-and-firmware-updates-currently-2020-2021.113473/
Most of these options are pretty solid - I have used similar on a VW RNS 850 to get the latest firmware and maps.
The only other issue is if your maps are on DVD (most likely), SD card (less flexible) or hdd.
If you are a bit reticent then Chris_coz's link is the easiest option.
To upgrade you can probably get Bluetooth streaming either using an ami connector
https://audistream2air.com/products/bluetooth-a2dp-adapter-for-audi-skoda-and-vw-3gen
Or a full on connection
https://upgrademyaudi.net/product/bluetooth-and-aux-module-for-audi-with-mmi-3g-navigation/
Good luck!