you don’t have to DIY anything, it’s there to buy it separately.
But when I tried to buy one from ali, I got a not working one (it was to long, and didn’t make electric contact), the they sended me the wrong model one (the bigger), and then they sended me the wrong color one (black, and I wanted green, the first two were green). Then they give up, and just returned my money (aside the 0.8$ for the shipping the second one)
There are some updates on it later, I should update it again now, just didn’t botherd.