This post gives a full explanation of how this feature has been implemented.
If you just want to use this feature in a Mailchimp campaign, all you need to do is make a copy of a Mailchimp campaign that already uses this feature (and probably the save to Calendar feature as well)
Once the user clicks on the Yes or Sorry buttons, they are redirected to a Squarespace page where they are asked to confirm
This will result in an email being sent to email@example.com, and an entry being created in a shared Google Sheet - RSVP
Details about how this is implemented are described below.
We use Mailchimp to let people know about meetups.
It's difficult to know who's going to come. Often we've then sent out Mailchimp/email, then had to followup with a text message asking for a reply which may or may not come, so then revert to phone call, which is all too time consuming.
Need a simple way for folks to respond with Yes or No if they're coming to a meeting.
Also need a reliable way to know if someone has read or opened their email about the event.
Add a "I'm coming" and "Sorry can't come" button to the Mailchimp campaign.
The button takes them to a simple Squarespace RSVP page with a Form where they confirm their attendance.
Squarespace records their response & can generate an email, and/or save the response in a Google Sheet.
Here is the Web address (URL) to include for the Yes I'm coming Button
And for the No Button
Mailchimp merge codes can be found here.
Probably only need to use
for email and name of the Mailchimp recipient, and the campaign's subject line. Squarespace will add the date & time.
Folks creating Mailchimp campaigns would just need to copy a simple sample campaign that includes the RSVP buttons, and so wouldn't have to be concerned about the URL encoding.
Read about Squarespace hidden fields in forms here.
See other post about how to create events and be able to save them to your calendar from the MailChimp email.
This is cheap and cheerful and should fulfil the purpose of recording RSVPs