All the command line options of FPGA-Bitstream can be shown by calling the help menu of VPR. Here are all the FPGA-Verilog-related options that you can find:
FPGA-Verilog Supported Option::
--fpga_bitstream_generator
..csv-table:: Commmand-line Option of FPGA-Bitstream
:header:"Command Options", "Description"
:widths:15, 30
"--fpga_bitstream_generator", "Turn on the FPGA-Bitstream and output a .bitstream file containing FPGA configuration."