Assets not loading when deploying to Heroku

Hi there! I have deployed this (after forking) to Heroku, but for some reason, none of the assets are loading. I’m fairly new to the language and I have a feeling that maybe some environmental variable might be misconfigured or something?

The front page loads perfectly fine, but not as intended. I went to check the developer tools and realized that it was doing a GET call from localhost, which I don’t believe is right?

GET http://localhost:43751/css/app-b358ab485f4965187a0366829058b5e7.css?vsn=d net::ERR_CONNECTION_REFUSED

GET http://localhost:43751/js/app-47ffdb6029e02e02cf2f5c4f4e2c7e4e.js?vsn=d net::ERR_CONNECTION_REFUSED

localhost:43751/images/til-logo-144x144-866373717b4dc8f05b886baaf7abae3b.png?vsn=d:1 

GET http://localhost:43751/images/til-logo-144x144-866373717b4dc8f05b886baaf7abae3b.png?vsn=d net::ERR_CONNECTION_REFUSED

Error while trying to use the following icon from the Manifest: http://localhost:43751/images/til-logo-144x144-866373717b4dc8f05b886baaf7abae3b.png?vsn=d (Download error or resource isn't a valid image)

Not sure if the config needs to be changed here: tilex/config/config.exs at master · hashrocket/tilex · GitHub since this is where I find localhost only existing or if it needs to be added to the Heroku config vars, but I have inputted in the SECRET_KEY_BASE on Heroku.

The dyno is using: web MIX_ENV=prod mix phx.server and made sure it’s pointing to my app.
Sorry if I’m not providing all the information needed, so please let me know if I’m missing something.