To make subscribers work, create a Tally/MailerLite/ConvertKit/Beehiiv/Mailchimp/Formspree form and replace PASTE_SUBSCRIBER_FORM_ENDPOINT_HERE in subscribe.html.
Set the form redirect to https://upkeepalerts.com/subscriber-thank-you.html.
The assessment form already points to https://tally.so/r/zxgK4a.