matrix-org/bridging

Hey all. I'm following the instructions on https://matrix-appservice-slack.readthedocs.io/en/latest/getting_started/ using docker. When I run the first docker run -v .... it doesn't seem to do anything, but no error is generated. Then if I run docker run -v /path/to/config/:/config/ matrixdotorg/matrix-appservice-slack (with config path changed) I get this error from docker:
node:internal/fs/utils:344
throw err;
^

Error: ENOENT: no such file or directory, open '/config/slack-registration.yaml'
at Object.openSync (node:fs:585:3)
at Object.readFileSync (node:fs:453:35)
at Cli.loadYaml (/usr/src/app/node_modules/matrix-appservice-bridge/lib/components/cli.js:226:29)
at Cli.startWithConfig (/usr/src/app/node_modules/matrix-appservice-bridge/lib/components/cli.js:219:30)
at Cli.run (/usr/src/app/node_modules/matrix-appservice-bridge/lib/components/cli.js:157:14)
at Object.<anonymous> (/usr/src/app/lib/app.js:98:5)
at Module._compile (node:internal/modules/cjs/loader:1103:14)
at Object.Module._extensions..js (node:internal/modules/cjs/loader:1155:10)
at Module.load (node:internal/modules/cjs/loader:981:32)
at Function.Module._load (node:internal/modules/cjs/loader:822:12) {
errno: -2,
syscall: 'open',
code: 'ENOENT',
path: '/config/slack-registration.yaml'
}