Hi Nilesh Ravaliya
The community document that I share only illustrates the relocation of code and data, but you could use, for example, the __RODATA(bank) define to place rodata into a flash section defined in the linker script.
This will save data when you download the code into the flash, but if you want to place your data in runtime, you going to need to use the Flash APIs from the SDK, you could check the flash example code, which demonstrates how to program user data into the last section memory.
Hope this helps, please let me know if you have any question.
Best regards