Hi @burhanhagi
To avoid your linker script modifications getting overwriten you can un-tick the Manage linker script
diego_charles_0-1715105312087.png
But this may not be the best solution since MCUXpresso will not longer update the linker script.
This section should be included to new project when the FreeRTOS OS is selected. See the below snapshot.
diego_charles_1-1715106201196.png
diego_charles_0-1715106165203.png
Now, if you do not want to create a new project, you can use the Manage SDK options and select FreeRTOS.
diego_charles_3-1715106469120.png
diego_charles_4-1715106510015.png
After clicking OK the below window will pop-up. Please consider that the IDE will ask if you wish to update your current SDK drivers, depending on your project and its configuration this could, in the worst scenario some clonficts, just be aware of that.
diego_charles_2-1715106452511.png
After buiding, you should see the missing section.
I really hope this could help you
Diego