UnhandledPromiseRejectionWarning

Hello !
First of all I want to tell you that I love your module!
Here is the mistake I come across:

(node:20550) UnhandledPromiseRejectionWarning: Error: (SSH) Channel open failure: open failed
    at SSH2Stream.onFailure (/usr/src/app/node_modules/ssh2/lib/client.js:1205:13)
    at Object.onceWrapper (events.js:421:26)
    at SSH2Stream.emit (events.js:314:20)
    at SSH2Stream.EventEmitter.emit (domain.js:486:12)
    at parsePacket (/usr/src/app/node_modules/ssh2-streams/lib/ssh.js:3455:10)
    at SSH2Stream._transform (/usr/src/app/node_modules/ssh2-streams/lib/ssh.js:701:13)
    at SSH2Stream.Transform._read (_stream_transform.js:205:10)
    at SSH2Stream._read (/usr/src/app/node_modules/ssh2-streams/lib/ssh.js:253:15)
    at SSH2Stream.Transform._write (_stream_transform.js:193:12)
    at writeOrBuffer (_stream_writable.js:352:12)
(node:20550) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). To terminate the node process on unhandled promise rejection, use the CLI flag `--unhandled-rejections=strict` (see https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode). (rejection id: 12)

I run an SSH command in a for loop in an asynchronous function and I don’t understand why I always have this error

No repository file or test is named. Start by reproducing the asynchronous SSH command loop described in the report, then inspect the stack frames in node_modules/ssh2/lib/client.js and node_modules/ssh2-streams/lib/ssh.js. Done means identifying the rejected operation and documenting or correcting how the caller handles that rejection.