This step is needed for Polylang Pro (or Polylang for WooCommerce) only. Users of the free version may directly jump to the next step.
You receive the key when you purchase a license. You get your license key in the purchase receipt or on your Account page > License keys tab.
You must enter the license key in the License keys module by going in Languages > Settings > License keys module.
Enter the license key in the field as in the example shown below and then click on ‘Save changes’.
Now the license key is associated to your site. During one year, you will be able to receive updates in your WordPress dashboard as usual for wordpress.org plugins. You will need to renew your license to get updates after one year.
NB: If you purchased the Polylang Business Pack, you received 3 license keys, one for Polylang Pro, one for Polylang for WooCommerce and one for the Polylang Business Pack You must enter the first two license keys in Polylang settings to receive the plugins updates. The third one will be used only to renew your license.