Newsletter Popup
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To find the settings for this, go to Online Store > Theme in your admin screen and click Customize. Once inside the Customizer, at the very bottom find Theme Settings and click on it.
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In Theme Settings, click on Newsletter Popup to see the settings. You have three options here:
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You can display the default sign-up form, which stores users’ email address under Customers in your admin screen. You can display HTML if you want to copy/paste embed code from a third-party newsletter service, like Mailchimp or Convertkit. Or you can display a call-to-action button that links to whatever you want. On the demo, it’s set to the default sign-up.
If you don’t want this, uncheck Show Newsletter.