Hello
I think you need to open a support case on the support site of OusSystems.

https://www.outsystems.com/goto/submit-support-case

Also, check this post that might help
https://www.outsystems.com/forums/discussion/74069/unable-to-connect-server-error-503/

Also here documentation is here
https://success.outsystems.com/support/troubleshooting/application_development/personal_environment_unavailable_http_503/

Regards,

Daniel