How do I update the repository of a Heroku app?

I am trying to update a repo on Heroku due to finding an error in my index.js file. After using heroku logs --tail, I noticed that:
Heroku Screenshot

I misspelled “config”, so I fixed the file. I tried to wipe the old repo using heroku git:remote -a <appname>, followed by git add ., git commit --am, and git commit push master to create a new one. However, opening the app begets the same error. How am I to update the repo so that the update to index.js is read?

I also followed the instructions of this Stackoverflow question, but nothing seemed to change. Thanks to any help in advance.