Tacx Training Desktop App pairing

I have just downloaded Tacx Training Desktop App and made login but bluetooth icon is greyed out. I think the application does not detect it even if it is enabled (I have integrated bluetooth in my laptop).

I don't have an ANT+ dongle.

Which kind of bluetotooth does it support? In case I need to buy additional hardware what do you suggest? Bluetooth or ANT+ dongle?

I saw that there is an ANT+ antenna on the Garmin store https://www.garmin.com/it-IT/p/690897/pn/T2028/ but

Are there compatible ANT+ dongles?