Error running script to Change the algorithm from RS256 to HS256, and use the public key as the secret key for the HMAC.

[emilyanncr]

ecro0@MN-C02YF0MJJG5L ~ % git clone https://github.com/Sjord/jwtdemo.git
Cloning into 'jwtdemo'...
remote: Enumerating objects: 42, done.
remote: Counting objects: 100% (3/3), done.
remote: Compressing objects: 100% (3/3), done.
remote: Total 42 (delta 0), reused 1 (delta 0), pack-reused 39
Unpacking objects: 100% (42/42), done.
ecro0@MN-C02YF0MJJG5L ~ % cd jwtdemo
ecro0@MN-C02YF0MJJG5L jwtdemo % ls
FirebaseRS256.php common.php private.pem
MishalHS256.php composer.json public.pem
README.md composer.lock publickeyhs256.php
base.php hs256.php rs256.php
ecro0@MN-C02YF0MJJG5L jwtdemo % php publickeyhs256.php

Warning: require(/Users/ecro0/jwtdemo/vendor/autoload.php): failed to open stream: No such file or directory in /Users/ecro0/jwtdemo/publickeyhs256.php on line 2

Fatal error: require(): Failed opening required '/Users/ecro0/jwtdemo/vendor/autoload.php' (include_path='.:') in /Users/ecro0/jwtdemo/publickeyhs256.php on line 2