Currently using a CRUD library from packagist: 
https://packagist.org/packages/bjsmasth/php-salesforce-rest-api
It requires you to put a username/password in code, so not great.

You'll need to create a Salesforce Connected App:

• Go into Setup - Platform Tools - App Manager
  https://worldcouncilofcreditunions.lightning.force.com/lightning/setup/NavigationMenus/home
  
• New Connected App (Top Right)
  • Enable OAuth
  • Set Callback URL for app
  • Set Scope - For CRM I set "Full Access" for now
  • Uncheck Proof Key
  • Save
• View App
  
• Consumer Key/Secret - Manage Consumer Details
• That Key/Secret goes into Code

That should get php to talk to salesforce...