Function to print Cookie Consent notice to wp_footer. Intended for functions.php. Check options. Demo: https://codepen.io/StephenScaff/pen/OZeGYz/

cookie-notice.html

<!-- 
Cookie Consent Notice
@example https://codepen.io/StephenScaff/pen/OZeGYz/ 
-->
<link rel="stylesheet" type="text/css" href="//cdnjs.cloudflare.com/ajax/libs/cookieconsent2/3.0.3/cookieconsent.min.css" />
<style>
@media (min-width: 32em) {
  .cc-window.cc-banner {
    padding: 1.5em 1.8em
  }
  .cc-message {
    font-size: 0.9em;
    line-height: 1.4
  }
  .cc-compliance {
    padding-left: 4em
  }
}
</style>
<script src="//cdnjs.cloudflare.com/ajax/libs/cookieconsent2/3.0.3/cookieconsent.min.js"></script>
<script>
window.cookieconsent.initialise({
 cookie: {
    domain : "/",
    name: "cookie_consent",
  },
  palette:{
    popup:  { background: "#e8ecf7"  },
    button: { background: "#181818"},
  },
  content:{
    message: "We use cookies to offer you a better browsing experience and analyze site traffic. If you continue to use this site, you consent to our use of cookies",
  },
});
</script>

gr-cookie-notice.php

/**
 * Cookie Compliance Notice
 * Prints Cookie Consent css/js requirements to wp_footer() via nowdocs
 * @see https://cookieconsent.insites.com/documentation/javascript-api/
 */
add_action('wp_footer', 'gr_cookie_notice');

function gr_cookie_notice() {
echo <<<'HTML'
<link rel="stylesheet" type="text/css" href="//cdnjs.cloudflare.com/ajax/libs/cookieconsent2/3.0.3/cookieconsent.min.css" />
<style>
@media (min-width: 32em) {
  .cc-window.cc-banner {
    padding: 1.5em 1.8em
  }
  .cc-message {
    font-size: 0.9em;
    line-height: 1.4
  }
  .cc-compliance {
    padding-left: 4em
  }
}
</style>
<script src="//cdnjs.cloudflare.com/ajax/libs/cookieconsent2/3.0.3/cookieconsent.min.js"></script>
<script>
window.cookieconsent.initialise({
 cookie: {
    domain : "/",
    name: "cookie_consent",
  },
  palette:{
    popup:  { background: "#e8ecf7"  },
    button: { background: "#181818"},
  },
  content:{
    message: "We use cookies to offer you a better browsing experience and analyze site traffic. If you continue to use this site, you consent to our use of cookies",
  },
});
</script>
HTML;
}