We have requested the SolarWinds Alert Integration application from ServiceNow store store.servicenow.com/sn_appstore_store.do , but it’s not reflecting on our instance
Do you mean your Orion Instance or SN instance? Have you looked at this guide? I at https://documentation.solarwinds.com/en/success_center/orionplatform/content/core-servicenow-how-it-works.htm