illegal option: --port=#####

[Ricoledan]

After integrating https://github.com/manyuanrong/deno_mongo into my application, I receive an illegal option error for "--port", both locally and when deployed on Heroku.

I'm specifically using https://deno.land/x/[email protected]/mod.ts

2020-11-26T05:27:08.450247+00:00 heroku[web.1]: Starting process with command `deno run --allow-net=:${PORT} --allow-env --allow-read --allow-write --allow-plugin --cached-only --unstable src/server.ts --port=${PORT}`
2020-11-26T05:27:11.019682+00:00 app[web.1]: Check file:///app/src/server.ts
2020-11-26T05:27:21.611900+00:00 app[web.1]: error: illegal option: --port=52201
2020-11-26T05:27:21.666634+00:00 heroku[web.1]: Process exited with status 1
2020-11-26T05:27:21.709754+00:00 heroku[web.1]: State changed from starting to crashed

Procfile:
web: deno run --allow-net=:${PORT} --allow-env --allow-read --allow-write --allow-plugin --cached-only --unstable src/server.ts --port=${PORT}

Deno version

deno 1.5.4 (bc79d55, release, x86_64-unknown-linux-gnu)
v8 8.8.278.2
typescript 4.0.5