Hello @kensu,
The evkmimxrt1160_ota_mcuboot_basic_cm7 is an example of an application; it is not the MCUboot bootloader itself. The actual bootloader is the example called mcuboot_opensource_cm7.You must load the MCUboot bootloader before loading the application.
Please refer to the README files of both examples, as they contain important information.
Additionally, MCUboot has two sections for storing images, as shown in the example_board_readme file of the mcuboot_opensource_cm7 project:

Your application could be placed in the primary slot, which is why the evkmimxrt1160_ota_mcuboot_basic_cm7 example is located in that memory region.
You need to modify your FreeRTOS_hello application to be placed in this section. You can use MCUXpresso to achieve this. Additionally, the size of the memory section will be determined by the size of your application. It does not necessarily have to use the entire space, but it must not exceed it, because if it does, it will overflow into the second memory section, potentially corrupting both images.
Note: Your application must have specific configurations for the MCUboot bootloader to accept your image. Here's an example taken from the example_board_readme:

Finally, is there available an MCU Bootloader Reference Manual, if you would obtain more information available on this page:

If you experience any issue, do not hesitate to let me know.
BR
Habib