I have been trying to create my own external application using Oauth, but I get to filling out the details for the callback URL and Identity link URL (and the name), which creates fine, but when I go to activate the integration I get greated with a "Sorry, something went wrong. Please try again later.", and the only error I get is from the debug.log file within Magento.
[2020-10-08 16:02:22] main.DEBUG: URI '/admin_13rc6p/admin/integration/tokensExchange/id/8/reauthorize/0/key/0ed0706f89d9950b82de796f028519b5f67df267cb337095fa255da0d52db82b/?form_key=hljjqv6G0SmuLm9g&_=1602172897038'' cannot be accessed with GET method (Magento\Integration\Controller\Adminhtml\Integration\TokensExchange) [] []
[2020-10-08 16:02:22] main.DEBUG: Request validation failed for action "Magento\Integration\Controller\Adminhtml\Integration\TokensExchange\Interceptor" {"exception":"[object] (Magento\\Framework\\App\\Request\\InvalidRequestException(code: 0): Invalid request received at /var/www/magento-install.com/lib/internal/Magento/Framework/App/Request/HttpMethodValidator.php:69)"} []
(I replaced my domain with magento-install.com)
I have followed the guides on https://devdocs.magento.com/guides/v2.4/get-started/authentication/gs-authentication-oauth.html, but still no luck with getting it to activate.
Any suggestions?