Embed mailchimp code for popup signup form

Hello,

I went through your link https://kriesi.at/support/topic/where-to-embed-code-snippet-for-popup-signup-form/?login_error

Tried all the suggestions, but none of them work. I don’t want to use a plugin to do the job.

Did a phpcode check on the suggested code mentioned in the above link. There is a code error.

function custom_code_mc(){
?>
// YOUR CODE GOES HERE
<?php
}
add_action('wp_footer', 'custom_code_mc');

Here’s the result from the code check: PHP Syntax Check: Parse error: syntax error, unexpected ‘}’, expecting end of file in your code on line 3

Any suggestion on how to fix the code and/or how to embed the mailchimp script so the signup form pops up on the home page?

Thanks,

Nik