Upgrade Service via CI

I have Jenkins job, which builds a container from repository and push it to DockerHub.
docker build -t example/api:latest .
docker push example/api:latest

I want to create another Jenkins job, which will upgrade specific service with latest container .
Right now I manually click “Edit” on Service in Rancher, in Docker Image field it has “example/api:latest” and then I just click “Upgrade”.

How could I automate it?

Any solution, how to do it?
Is it possible to automatically upgrade rancher services?

In 1.x, Receiver webhooks can trigger an upgrade. In 2.x, something like Keel.