Here is the easiest way for you to activate the License Key for the plugins

Divi Next Website → Your Account 

Sign in to your account on our website: and then, copy the License Key from your account.

WordPress Dashboard → Plugins

Head to your WordPress Dashboard and go to Plugins, here you paste the License Key onto the License Key field


Save Changes → Activate License

After applying the License Key to the License Key field, you have to first click ‘Save Changes’. And then click on ‘Activate License’.

Here's a video that shows you the process as well:

I hope this was helpful

Thank you