Calibration parameters of the Flexible Logic Unit (FLU) are stored inside the DPRAM.
Use the genertaed file ram_logger.csv  to get the offset address of the parameters you want to change e.g. Ki and Kp.
Open a memory window at address 0x60000000 (base address of the DPRAM) in your debugger and change the Ki and Kp as wanted.
Then in the APB FLU slave, in register CR set the bit 2 for the calibration to be applied on the FLU algorithm: Open a memory window at address 0xC4074000 and write at offset 0x60 the value 0x4.