First confirm that your own connection works by opening an unrelated site. Try another page on the affected service and, if safe, a private window or different network. Note the exact error and time. Then check the service's official status page and community reports.
Do not repeatedly submit a payment, form, or upload while testing; a delayed response can still have completed the action. If only your account or device is affected, describe it as a local or account-specific failure rather than a site-wide outage.
A useful report says what you tested and what happened, without exposing private account data.
Akousa