You must have account with a third party newsletter service, such as MailerLite, MailChimp, ConvertKit, Drip or GetResponse, kindly create a support ticket if you need help with any other newsletter service provider.

Refer to your preferred newsletter provider.
Note:
– Different newsletter provider may display differently
– If there is any update from the respective newsletter, kindly refer to their documentation.

MailerLite: https://www.mailerlite.com/video-tutorials/embedded-forms-overview

MailChimp: https://mailchimp.com/help/add-a-signup-form-to-your-website/

Flodesk: https://help.flodesk.com/en/articles/3200763-how-to-add-an-opt-in-form-to-your-website

ConvertKit: https://help.convertkit.com/en/articles/3085392-how-to-embed-forms-on-wordpress-using-javascript#where-to-get-the-embed-code

GetDrip: https://help.drip.com/hc/en-us/articles/4424710461197-Create-an-Embedded-Form

GetResponse: https://www.getresponse.com/help/how-do-i-embed-an-inline-content-s-snippet-code-on-my-website.html