Auto tune for fixed wing

I am working on QGC latest version and trying to setup trainer 40 fixed wing but unable to find auto tune function. Can anyone please guide me ?

If you are using PX4 then the answer is - Auto tune in not a supported feature.

Is their any other solution for auto tuning for fixed wing?

@mirza_anas @jimdgit Fixedwing autotuning for attitude control loops have been added in Auto-tuning of angular rates and attitude controllers (FW version) by bresch · Pull Request #18330 · PX4/PX4-Autopilot · GitHub

You will find how to enable the functionality in the PR

Wow thanks @Jaeyoung-Lim! I did not know that feature had been deployed yet.
Here is the doc page: