May I ask whether the device in the picture has a fixed output or an adjustable output
Any model of ADP7104 can be used to get an adjustable output. But to answer your question, the LDO, "ADP7104ACPZ", on your schematic is the adjustable model with output voltage of 1.22V. To use the model in adjustable mode, add a resistor divider network on the SENSE/ADJ pin and use 1.22V as Vadj to get the adjustable output voltage. Here is the formula from the datasheet:
I also noticed on your schematic, your resistor network is incorrect to yield Vout = 3.3V. Try changing the bottom resistor by referring to the formula.