command line – How do I specify program arguments to subtitle-edit installed via snap?

I’ve installed subtitle-edit via snap.

$ snap install --edge subtitle-edit

I want to use the command line to convert but when I do mono complains about unknown arguments.

$  Jurassic Park: subtitle-edit /convert subtitle.sup subrip
SE data folder is /home/pdouble/snap/subtitle-edit/7/se_data
Cannot open assembly '/convert': No such file or directory.

Help shows mono arguments, not subtitle-edit:

$  Jurassic Park: subtitle-edit --help
SE data folder is /home/pdouble/snap/subtitle-edit/7/se_data
Usage is: mono (options) program (program-options)

Development:
    --aot(=<options>)      Compiles the assembly to native code
    --debug(=<options>)    Enable debugging support, use --help-debug for details
    --debugger-agent=options Enable the debugger agent
    --profile(=profiler)   Runs in profiling mode with the specified profiler module
    --trace(=EXPR)         Enable tracing, use --help-trace for details
    --jitmap               Output a jit method map to /tmp/perf-PID.map
    --help-devel           Shows more options available to developers

Runtime:
    --config FILE          Loads FILE as the Mono config
    --verbose, -v          Increases the verbosity level
    --help, -h             Show usage information
    --version, -V          Show version information
    --version=number       Show version number
    --runtime=VERSION      Use the VERSION runtime, instead of autodetecting
    --optimize=OPT         Turns on or off a specific optimization
                           Use --list-opt to get a list of optimizations
    --attach=OPTIONS       Pass OPTIONS to the attach agent in the runtime.
                           Currently the only supported option is 'disable'.
    --llvm, --nollvm       Controls whenever the runtime uses LLVM to compile code.
    --gc=(sgen,boehm)      Select SGen or Boehm GC (runs mono or mono-sgen)
    --handlers             Install custom handlers, use --help-handlers for details.
    --aot-path=PATH        List of additional directories to search for AOT images.

I’ve also tried the following:

$  Jurassic Park: subtitle-edit -- /convert subtitle.sup subrip
SE data folder is /home/pdouble/snap/subtitle-edit/7/se_data
Cannot open assembly '/convert': No such file or directory.
$  Jurassic Park: subtitle-edit -- -convert subtitle.sup subrip
SE data folder is /home/pdouble/snap/subtitle-edit/7/se_data
Unknown command line option: '-convert'
$  Jurassic Park: subtitle-edit -convert subtitle.sup subrip 
SE data folder is /home/pdouble/snap/subtitle-edit/7/se_data
Unknown command line option: '-convert'
$  Jurassic Park: subtitle-edit --convert subtitle.sup subrip
SE data folder is /home/pdouble/snap/subtitle-edit/7/se_data
Unknown command line option: '--convert'
$  Jurassic Park: subtitle-edit -- --convert subtitle.sup subrip
SE data folder is /home/pdouble/snap/subtitle-edit/7/se_data
Unknown command line option: '--convert'

How do I specify arguments to this program?