Unable to access DigitalOcean DNS extension in Plesk: ERROR: Declaration of PleskApiClient

Symptoms

When accessing DigitalOcean DNS extension in Plesk, the page fails to load with the error message:

ERROR: Declaration of PleskApiClient::request($request, $mode = self::RESPONSE_SHORT) must be compatible with PleskXApiClient::request($request, int $mode = self::RESPONSE_SHORT): PleskXApiXmlResponse (Client.php:21)

Cause

This is a DigitalOcean DNS extension bug with ID EXTPLESK-5375, which has already been fixed in extension version 1.4.3-649.

Resolution

Update the DigitalOcean DNS extension.