On-Premises PACS:
Yes, you can use a DICOM viewer that meets the following requirements.

• Compliant with DICOM Standard.
• Supports Study Root Query/Retrieve or Patient Root Query/Retrieve.

For detail, please refer to: Documents > Install Manual > Connect To DICOM Viewer
Also, for the technical information, please refer to: Documents > DICOM Conformance Statement

Cloud PACS:
No, you cannot do so at the moment.
This is because it does not support DICOM Query/Retrieve SCP at the moment.
We plan to support it in the future.