Error code 1, Access Denied

[pruggirello]

Hey! Thanks for making this api. I had given up last year after having been unable to find anything useable in my React application. I have kind of a weird issue, I installed the api and used it once with success. I was able to add my email to my group and verified it inside my MailerLite account. When I went to make a component that did that (it was originally just raw html inside another component), I got an error code saying access was denied. Specifically, it says:

"Access to XMLHttpRequest at 'https://api.mailerlite.com/api/v2/groups/104625980/subscribers' from origin 'http://localhost:3000' has been blocked by CORS policy: Request header field x-mailerlite-apikey is not allowed by Access-Control-Allow-Headers in preflight response."

Here is my MailerLite.js file:
const MailerLite = require('mailerlite-api-v2-node').default;
var apikey = example_api_key;
const mailerlite = MailerLite(apikey);
export default mailerlite;

Here is the function I am using to post my new subscriber:
addEmailSub = () => {
var email = document.getElementById("email").value;
mailerlite.addSubscriberToGroup(104625980, email);
}

Any input would be appreciated!

[MrJibus]

According to : https://developers.mailerlite.com/docs/authentication

API key is designed for server-side usage and it cannot be used directly on the client side making AJAX calls because it will be exposed publicly. So it is forbidden due to security concerns.