FT232RL USB to serial : 5V or 3.3V set by jumper
USB to TTL Adapter Based on FT232RL
Slightly different board but this page confirms the comments.


+3.3V and +5.0V signal Level Support using SMD jumper.
Voltage Level on RXD, TXD pins: 5.0V (Default), 3.3V through smd solder type jumper.

5V Jumper is hardwired by default.  Cut trace with knife and solder wire to 3.3V tab.