Adding Hostinger as server provider is fairly easy, head over to hostinger.com and login to your account.

Next, click on the avatar at the top right, and then press "Security" and go to the "API" tab, or click this quick link.

In here, you can create a fresh API key:

After creation you'll be presented with the API key, copy this key to your clipboard, and then you can go back to Ploi.io and add it as a server provider in your profile. Just enter the API key and you're all set!

Important: You will need to have an active payment method in your Hostinger account before you can add the API key to Ploi.