Uploading requested documents (outland application online)

[azo2022]

Hi, I applied for outland spousal sponsorship online (not paper) on Feb. 2022. I am now asked to provide an additional police certificate.
1) Can I upload supporting documents through GcKey? The application portal is not allowing me to access my application.
2) Anyone has any good/bad experience with providing supporting documents through web forms?
Thanks!