QWIIC MP3 That I am Hacking

I’m very familiar with hardware, but not as familiar with Software. For reasons I will not go into, I’m prototyping a system using the QWIIC MP3 board and I have (intentionally) removed the processor from the board so I could access the RX and TX pins directly on the the MP3 chip (technically, it is a WT2003S-16S). I was wondering if the source code you have in the zip file for that product is for the QWIIC system interface (I think it is an I2C), or if the code is for sending commands to the MP3 chip. I’m looking for the Arduino code to send a “Play file #X” to the MP3 Chip and am hoping you have the .h file and any .cpp files I need so that I can write a simple command to play the file on the MP3 chip.

I know this is a bit out in left field, but I’m hoping the code exists or someone has a simple example for the required Arduino code. The answer may be in the code I’m looking at, and I’m too dense to understand it (e.g. how do I know what pin the RX pin on the WT2003S should be wired to on the Arduino)?). I was shocked when I realized that many of the examples I was looking at come with a beer license. I promise to abide by that license agreement. And if I never meet Nathan, I promise I’ll drink one for him - I believe that is an implied part of the license.

In the end, I’m planning to design a board that will use the MP3 part and I want to prototype it to make sure I completely understand how to command it the way I want to command it. I have a standalone Arduino I’m using to prototype my system. In my ideal little world, I will not need to read the MP3 part, only command it and have it play a given file number (e.g. file number 1 is the first file written to the SD card).