The steps are very simple and Laravel works out of the box to support on Heroku. One major important thing is Laravel will not work without the APP_KEY variables so make sure you create that variable via the UI from your App settings or use the command as described below, how Laravel works on your local environment is that it has the .env file to provide the APP_KEY but Heroku doesn't need that to function.
First off in your Laravel project make sure you initialize the git repository where you have composer.json and other files. Heroku need composer.json in your root folder to run builds.
Okay, let's start with login in to Heroku,
Then create new application
Set up buildpacks, you might not need both since you might do the npm stuff in your local and deploy the complied code.
heroku buildpacks:add heroku/php heroku buildpacks:add heroku/nodejs
Set App related configs.
heroku config:set APP_KEY=YOURBASE64KEY
Replace the YOURBASE64KEY with your key.
Deploy Laravel App to Heroku
git push heroku master