FCM not supported in safari and ie. But we have a scenario where in the backend server (microservice) when a process completes it need to intimate client. What is the best alternative to achieve the above requirement?

To identify the particular process status. we are hitting the microservice with an regular interval of 5 minutes. Expecting microservice to send a message to client about the process status (on complete, on fail). In our web app we display the completed count, UI – like notification count.