2018 car should be able to have a genuine Audi smartphone interface activation completed via a dealership or authorised 3rd party. Updating firmware alone will not get you ASI, just bug fixes and performance enhancements etc.
there are companies who can perform unofficial activations of ASI, myself included.
The following is a cut and paste of some text I attach to all related posts I make:
There are no two ways about it! There are a lot of "professionals" out there performing unofficial activations. While we always tried to stay away from offering these we now have to in order to compete in todays marketplace.⠀⠀⠀⠀⠀⠀⠀⠀⠀
Unofficial Activations are carried out within a vehicle's control modules & systems, using the same software & coding as genuine activations however during general updates for vehicle software (for example while servicing or during repair works) any unofficial works may be overwritten & removed. Unofficial Activations of this type have no warranty & may invalidate parts of a vehicle's warranty. The trade-off between Official vs Unofficial is cost, an unofficial activation is cheaper.⠀⠀⠀⠀⠀⠀⠀⠀⠀
VAG Car Coding™ Limited does not use software downloaded from internet forums. We don't use pre-made solutions & templates complied by others. We don’t use others to complete our works, everything is IN HOUSE. We have taken the time to fully reverse engineer and test the systems involved & create individual code for everything we do, and because we fully understand the process from end to end we are able to recover from any issues.