using rf-count with bowtie-index

[EmiWe]

Hello, 

it seems that I am not using the right command for counting the reads.

I do not have a transcriptome reference so I am using the following in order to use bowtie-index:

$ ./rf-count -bi plasmid-index/plasmids map.bam

And then this error jumps up:

[!] Error: Invalid option. Please check the help

What am I doing wrong?

Thank you for your help!!!

Emilia