It should be near the thottle body.
I also type boost sensor Audi TT it shows up, I am unsure why it’s a misnomer. I believe you, but yeah I’m not that well versed.
The M in MAP stands for manifold.
The pressure sensor is not in the manifold. In fact, actual manifold pressure is modeled based on the upstream pressure sensor before the throttle body by calculating pressure drop over the throttle body.
I highly recommend understanding where everything goes and why before starting any tuning.