Example switch for handling multiple websites with MODX. In your /index.php: search & replace (+/- line 68)... $modx->initialize('web'); ...with this gist:

index.php

// $modx->initialize('web');
switch(strtolower(MODX_HTTP_HOST)) {
   case 'www.example.com:80':
   case 'www.example.com':
      $modx->initialize('my-example-context'); // context for example.com
      break;
      
   case 'www.example2.com:80':
   case 'www.example2.com':
      $modx->initialize('my-example2-context'); // context for example2.com
      break;

  default:
      $modx->initialize('web'); // default context
      break;
}