How to Work with Jumper Pads and PCB Traces
Adding a Solder Jumper
To add an intentional solder jumper, place the soldering iron's tip on the 3.3V side (left pad relative to the header pins facing down) and the center pad.
If you decide to set the FTDI back to its default of 5V, simply heat the intentional solder jumper with a soldering iron and move the solder back to the right side. Feel free to add more solder if necessary.
Certain PCBs already have a solder jumper connecting pads. You may just need to adjust the connection by removing the solder jumper.