Running the survey locally and having the PHP script on your server will likely not work due to Cross-Origin Resource Sharing (or "CORS") limitations. It is a security risk making a network request from your local machine to a remote server.
Sometimes, you need to be able to test your survey locally, and make constant changes,
before publishing it for good. You can turn off CORS by editing /public/submit.php
before you run npm run build (or /submit.php in your homepage folder
after you have built and deployed the survey) and uncommenting the header line of code.
See submit.php for more details.
Note that this is a security risk, and should only be used for testing. The code that allows CORS should be left commented when testing is complete.