Restrict access to specific people by adding their email addresses to an invite list. Each invited person receives an email with a link to the form, and only people on the invite list can sign in and submit the form.
How to enable this option
Open the form and click on the Settings tab.
Click on Access control in the left sidebar.
Select Only the invited people can submit the form.
Click Save changes and invite via email. The invitation editor opens.
Add one or more email addresses in the Send to field. Use Bulk Upload to add many at once.
Customize the Subject and Email body if you want.
Click Send email. Each invitee receives an email with a Get started button that links to the form.
Publish the form so the new setting takes effect.
What the invited person sees
When an invited person opens the form link, they see a screen titled The form is protected!. They can either click Login with Google, or enter their email and click Next to receive a 6-digit login code by email. After they paste the code on the Verify your email screen and click Verify, the form opens. The login code is valid for 10 minutes.
To explore the other access control options, see Managing access to a form.