Acess other project container registry with gitlab ci

I have 2 private project
In both of them with each new version there will be created a new image in container registry
My question is:
How to access container registry of second project from first in gitlab-ci?
I have to have both of them in order to perform end-to-end tests. I have searched documentation but solution doesn’t appear before me.

I want to add second project container as service in one of the stages.