[ssamadhi97]

Guess screenshots are mostly self-explanatory

If you don't have "Commandline Encoder" option as shown in second pic, you're missing foo_clienc

As for encoder parameters I picked in 3rd picture:
-4 = level of compression, many people seem to like -8 for highest compression but #@%& slow encoding; I prefer -4 for best speed / compression tradeoff (compression slightly worse than -5 (default), but much faster)
- = encode from stdin (this way foobar sends data to flac.exe without making a temporary wav file)
-o %d = output to file %d (actual filename will be filled in by foobar when encoding)