Extra external components for lm2596
Do you see a 5-pin device on the module? Look carefully, that is the LM2596, that is even printed on it in text.

The idea of such a module is is that it is "ready to use". So all you have to do is connect an input voltage at IN- and IN+, measure the output voltage at OUT+ and OUT-, then turn the screw on the bright blue trimmer until the output voltage is what you want.

The datasheet of the LM2596 does not show the exact schematic of this module. There are some extra resistors and a variable resistor (bright blue) to set the output voltage. The difference is small. The advantage of such a module is that it will just work as all that is needed is there already. If for example you would use the wrong type of capacitors or inductor, it would not work. That often confuses beginners. So I always recommend these modules. Heck, I'm lazy so I also use them myself!

You do not need any extra components.

You should not draw more than around 2 A at the output.

That's it.