Create the Mailchimp (Pop-up Form) for the Blog, is a fairly simple and quick process.
1. Log into your Mailchimp dashboard and go to Mailchimp > Navbar Vertical > Audience > Signup forms > Pop-up Form.
When you get to this part where you get to the "Pop-up Form Builder" where you can build your form and customise it as you wish.
2. The top bar that says "Connect your website to publish your pop-up on your site". Click on Connect Site.
3. In the field "Enter your website URL". Click on Get started.
4. It will generate a code that you must copy. Click on Copy To Clipboard.
You’ll need to add some code to the <head> of your website to get it connected.
5. Log into your Blogger dashboard and go to Themes > Customize ▼ > Edit HTML.
Press on Windows "CTRL+F" or on MAC "Command+F". Search <!-- Mailchimp -->
6. Just below you paste the generated code from Mailchimp. Click on Save.
7. Return to the Mailchimp window and click on the "Check Connection" button. And Ready.