Help compiling and executing functions

Hi, I've been trying to compile a cpp into wasm, in this case using SINGLE_FILE option.
It generates a JS file that loads the WASM from a BASE64 string, which is what I want.
Since my project can only have a single JS file, I've copied and pasted the Emscripten js code at the top of my main js file.
But I have no clue on how to call the C/C++ functions from it, of if I'm even getting the code to execute at all...

Can you guys please help me with a basic example?
I can't find anything on the subject on the internet, information about it is very escarce...