Hello,
The FS26 is not supported in the MBDT for S32K3.
Depending on the application you need to develop, you might be able to install MBDT for BMS on top of MBDT for S32K3 1.4.0. It is mandatory to have S32K3 1.4.0 for the BMS toolbox to work.
The FS26 SDK is included in the toolbox and integrated inside the S32Config Tool, but you still have to write custom code to use it. You can start by checking the rd33772c14vevm example (either EBtresos or S32Config Tool variant) to see how you can read and write from FS26's memory.
Best regards,
Sorin Bancila