Extension license is not applied to Plesk server right after purchasing it: You don't have a valid license

Symptoms

Right after purchasing an extension license for a Plesk server, the extension still offers to purchase a license in Extensions > My Extensions > extension_name:

CONFIG_TEXT: You don't have a valid license. You can buy one at the Plesk store

CONFIG_TEXT: This paid extension is not licensed. Some or all functions and features of the extension may not be available. Purchase a license to unlock all functions and features of this extension.

Cause

The extension license has not been retrieved yet.

Note: Recently bought keys are not uploads to Plesk instantly. They are received automatically during the daily task.

Resolution

1. Log into Plesk
2. Go to Tools & Settings > License Management
3. Click the Retrieve Keys button
4. Accept the keys provisioning