esp32-snippets | Sample ESP32 snippets and code fragments

I want to know how can I write a header file in C, that can send an AT command

From simplewikipedia header file:

In computer programming, a header file can be thought of as a dictionary a compiler uses if it comes across a word it does not understand.

From wikipedia source code:

The source code of a program is specially designed to facilitate the work of computer programmers.

You can't write a header file that will do an action. The source code does the "work" of the computer, header file serves as a dictionary.

I want to know how can I write a header file in C

There are plenty tutorials on how to write header files in C over the net. The tutorial on tutorialspoint is one of them.

if anyone can tell me how to write one or two commands of the BLE module

Opinion: rule of a thumb - google "github I want this" and you will get code samples.

libraries for all the features I'll be using in MC60, be it UART, BLE, GSM, GPS

Stackoverflow is not a coding service.

Start your way up or down. Create an abstraction. Create API and write libraries that support your abstraction. Work way up (or down) and create all relevant source files.

Arduino has many libraries you can use. AT commands are plain data you send through communication link - mostly through an universal asynchronous receive-transmitted (UART), but not only. The documentation you linked is exact - it lists all available AT commands you can use with your device. Read it.

can send an AT command to MC60 from the MCU and just fetch the response.

All the serial communications on arduino is described in Serial. You can get many examples of serial communications on arduino online. Note that arduino libraries are in C++, not in C. You can write your own abstraction for the uart communication (or have no abstraction at all). Download the datasheet/reference manual for your device, read it and start implementing the needed functionality in your program.

I want a script in C that can just customize the AT commands