The Flash Download Toolkit only operates on Windows based machines. Linux is not supported at this time.
Supported Operating Systems:
Windows® 10 (32- and 64-bit versions)
Windows® 8.1 (32- and 64-bit versions)
Windows® 7 (32- and 64-bit versions)
For the most current list & specific details, please refer to: https://www.renesas.com/en-us/products/software-tools/system-requirements.html#prog.