IndexNow error 422 Keylocation is not allowed

[TnT]

Affected version

v2.3.9

For a while now, I have been getting the following error messages:

ErrorException: IndexNow error: [422] Keylocation is not allowed. Please ensure the keylocation url belongs to the site mentioned in the host parameter

Stack Trace:

#0 src/XF.php(270): XF\Error->logError('IndexNow error:...', false)
#1 src/XF/IndexNow/Api.php(88): XF::logError('IndexNow error:...')
#2 src/XF/IndexNow/Api.php(34): XF\IndexNow\Api->request('/?key=REDACTED...', Array, 'IndexNow error:...')
#3 src/XF/Job/ContentIndexNow.php(84): XF\IndexNow\Api->index('/REDACTED...')
#4 src/XF/Job/Manager.php(275): XF\Job\ContentIndexNow->run(8)
#5 src/XF/Job/Manager.php(205): XF\Job\Manager->runJobInternal(Array, 8)
#6 src/XF/Job/Manager.php(89): XF\Job\Manager->runJobEntry(Array, 8)
#7 src/XF/Cli/Command/RunJobs.php(58): XF\Job\Manager->runQueue(false, 8)
#8 src/vendor/symfony/console/Command/Command.php(298): XF\Cli\Command\RunJobs->execute(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#9 src/vendor/symfony/console/Application.php(1040): Symfony\Component\Console\Command\Command->run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#10 src/vendor/symfony/console/Application.php(301): Symfony\Component\Console\Application->doRunCommand(Object(XF\Cli\Command\RunJobs), Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#11 src/vendor/symfony/console/Application.php(171): Symfony\Component\Console\Application->doRun(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#12 src/XF/Cli/Runner.php(115): Symfony\Component\Console\Application->run(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))
#13 cmd.php(17): XF\Cli\Runner->run()
#14 {main}