Create a new project for the processor type.
Copy the source files into the project folder.
Add the source files to the project.
Then you can build the project which will produce the hex file.

Hello sir I have doubt in mplabx ide I code and build the project but it is producing elf file .. not generating hex file I need hex file... Sir please help me how can I fix it?

 

Hello sir I have doubt in mplabx ide I code and build the project but it is producing elf file .. not generating hex file I need hex file... Sir please help me how can I fix it?

It should be producing the hex file as well. maybe you are looking in the wrong place.