Basically this is a JQuery snippet to fill a Google Form from a custom page by making a post request to url form on submit.
This snippet allows us to fill a google form hosting a custom form in our webpage. Of course fields should match original Google Form and be updated at all times.
Inspect your Google form picking each input's name's and link them to your custom form fields as explained in snippet. This is a fast and reliable way to store your form responses in a Google Spreadsheet without going into server side programming and developing an API integration.