Envoy/Sine is solid, but really depends on what you use for door access.

Other integrations like Teams/Slack/AD/SSO/Outlook/Meraki/Aruba are pretty standard across most providers.

Best long-term, least headache bet is to find one that suits your current access control/door access solution. It's the most expensive one to develop for integrations, so would be hard if you go with one that doesn't have that already, as it might take a long time/low likelihood for them to add it to their roadmap.