Follow the actual Wix tutorial here.
https://support.wix.com/en/article/corvid-tutorial-sending-an-email-on-form-submission
You need to be using the sendgrid.js and email.jsw backend files with this page code, otherwise it is not going to work for you.
import {sendEmail, sendEmailWithRecipient} from ‘backend/email’;
Also this line here.
const recipient = “dora@opendoormedia.ca”
Needs to be the email value on the page and not an actual email.
const recipient = $w(“#emailInput”).value;