Mutserve call does not work with CRAM file

[dana-obk]

Hello,

I am trying to run mutserve using .cram files as from documentation seems it supports it:

Usage: mutserve call [--baq] [--deletions] [--help] [--insertions] [--no-ansi]
                     [--no-freq] [--version] [--write-fasta] [--write-raw]
                     [--alignQ=<alignQ>] [--baseQ=<baseQ>]
                     [--contig-name=<contig>] [--level=<level>] [--mapQ=<mapQ>]
                     [--mode=<mode>] --output=<output> --reference=<reference>
                     [--threads=<threads>] [<input>...]
Call homoplasmic and heteroplasmic positions.
      **[<input>...]          BAM/CRAM files**
      --alignQ=<alignQ>     Minimum Align Quality
                              Default: 30
      --baq                 Enable BAQ
                              Default: false
      --baseQ=<baseQ>       Minimum Base Quality
                              Default: 20
      --contig-name=<contig>
                            Specifify mtDNA contig name
                              Default: null
      --deletions           Call deletions (beta)
                              Default: false
      --help
      --insertions          Call insertions (beta)
                              Default: false
      --level=<level>       Minimum Heteroplasmy Level
      --mapQ=<mapQ>         Minimum Map Quality
                              Default: 20
      --mode=<mode>         Specifify mutserve mode
                              Default: mtdna
      --no-ansi             Disable ANSI support
                              Default: false
      --no-freq             Use Frequency File
                              Default: false
      --output=<output>     "Output (txt or vcf)
      --reference=<reference>
                            Reference
      --threads=<threads>   Number of threads
      --version
      --write-fasta         Write fasta file
                              Default: false
      --write-raw           Write raw file
                              Default: false

This is my code:
mutserve call --reference rCRS.fa --output out_from_cram.vcf --threads 2 my_input.cram

But the program does not recognise the .cram file, and sees it as a sam file:
htsjdk.samtools.SAMException: Input file must be bam file, not sam file

Is there a way to solve this?