@Kekscast I doubt you had the wireless unit already unless you asked the shop to install it for you which they would have more than likely charged you for.
I got a Tarmac comp di2 ultegra / disc recently and had to buy it separately. It is very easy install and usually in the seat post. @GPLama has a good video on youtube of the install. You need the unit, 150mm di2 cable and the di2 tool (people say no but it is piece of mind). I also bought the climbing shifter as well like GPLama and love it.
The programming bit you get from it I dont use as I always use my computer for that. What is awesome is the gears view (i only show cassette gears), battery left, shifting mode, changing screens with the hood buttons and assigning them as needed.
Also on the 530 when I am about to go up or down on the front bracket it makes a noise and also has a visual on the screen telling me I have one more shift until it does so. I also use full synchro shift