Requesting assistance with library issue multiple definition of `' Error

Hi guys. I’d like to preface by saying that I am not a programmer. I have a decent knowledge of C but certainly not a professional by any standard. I have a project where I have my main function relatively short, and it simply calls sub-functions that are contained in other .h files in my project. This has worked fine for me previously.

One of these sub-function header files “CAN_handler.h” relies on a library called ESP32_CAN by tonton81 on Github. I can include the library in my CAN handler .h file and read/write to the CAN port with no issues at all.

Inside the CAN Handler, however, there is another library included, one that I have written, that also needs to include ESP32_CAN as it utilizes the CAN message struct and circular buffer contained inside the ESP32_CAN library. When I nest the keypad library inside the CAN handler and #include the ESP32_CAN library in the keypad library (or also include it in the CAN handler), I get an error on compilation that is displayed in this screengrab:

I have cut out all the unrelated parts of my code so that only the things relevant to this problem exist in this program. I will upload one in which the compile error occurs, and one where the contents of the can library are all commented out and the error does not occur.

The projects are here:

Also I know I’m not using Github correctly by doing this lol

Upon further investigation, I have found that I can uncomment all the contents of the CAN keypad library and leave the CAN Handler.h contents commented out the way I have it, and the error can be controlled by only commented out the line where I instantiate the keypad object.