Hi everyone-I just purchased a 2019 TCR Adv Pro Disc. This is the first time I'm riding an electronic groupset (and I love it!)

The bike has Shimano Ultegra Di2 but the Giant website doesn't say which model. I am wondering if I need to buy the wireless unit D-fly in order to connect my garmin to the Di2. I tried a few times to connect but was unable to. I am wondering if the bar end junction has built in wireless connectivity or do I still have to buy the wireless unit.

Finally, is the wireless unit a good investment if I have to buy?

Thank you,