How do I add checksum to hex image in CubeIDE?

I whish to make a main application for use with a custom bootloader.

The main application should be compiled to a hex file with all empty space above the app, filled with 0xFF and with some of the last bytes containing a checksum of the app image.

I found how to generate a hex here:

https://community.st.com/s/question/0D53W000002fOMySAM/how-does-one-generate-a-hex-file-from-stm32cubeide

But I haven't found how fill remaining space and make the checksum.

In MPLAB it is done like shown here:

So how do I do this in CubeIDE?