Is it not showing in the UI only?

Does it show when you run API call /api/external/v1/integrations/GetInstalledIntegrations?

Yes ,Is it not showing in the UI and 

 not  showing when i am  run API call /api/external/v1/integrations/GetInstalledIntegrations.

its only showing when i am run API call /api/external/v1/integrations/GetIntegrationDefaultInstance/{integrationIdentifier} 

Please create a support ticket so the team can investigate.

Could the Environment be wrong?
Show all would show it, but the UI might only query for instances inside Envirnoments

I found the solution by making a request to the following API endpoint:

POST /api/external/v1/integrations/CreateIntegrationInstance

Request Payload:

{
"integrationIdentifier": "Cloud",
"environment": "Default Environment"
}Response:{
"identifier": "6e31dd9e-39ac",
"integrationIdentifier": "Cloud",
"environmentIdentifier": "Default Environment",
"instanceName": "Cloud_1",
"instanceDescription": null,
"isConfigured": false,
"isRemote": false,
"isSystemDefault": false
}Now, the created integration instance also appears in the UI.Note: The instance will only be created and displayed in the UI if the provided integrationIdentifier matches an existing value in custom integrations.