Sure. From a quick look at the specs the trainer outputs ANT+ speed cadence and power and also supports ANT+ FE-C for trainer control. You can pair the trainer with your Fenix as a speed/cadence sensor and as a power meter if you want to. You can also pair it for FE-C control, though if you have another app controlling it, such as Zwift or Trainer Road you should not do this part since it may confuse the trainer.
Once you have the pairing set up you can just start an indoor cycling activity and it will work just fine.
Thank you for your quick response. I do not yet have the Tacx in my possession, I will soon receive it. I wonder how the indoor sport activity will be stored.
