FT232RL Chip pinout to flash Arduino Pro Mini
This is the standard FTDI Basic connections. CTS is an input to the module and is typically just connected to Gnd as seen on the right side here from the Arduino Promini schematic (so the FT232 is always Clear(ed) To Send, i.e. no flow control is used).

DTR may be broken out on one of the side holes.  RTS may work for you in place of DTR to create the reset pulse to start the bootloader code.  If not,  you may have to cut the trace and wire the RTS header pin to DTR. DTR is pin 2 on the FT232, use a meter and confirm it goes to one of the side holes, that way  you don't  have to try a solder a wire on to a pin.