Hi Chen Xin,
About how to generate ".hex" image file of CW V10.4 project.
In CW project Properties, select [C/C++ Build] -> [Setting] ->[Additional Tools]: select [Create Flash Image]

Then In [ARM Ltd Windows GNU Create Flash Image] select [Output file format]:

Then you can recompile the project and in [FLASH] target folder, you will find genrated ".hex" image file.
Wish it helps.