What is the best strategy when FE an BE are in different repositories?

[StijnDams]

We would like to include Cypress in our CI/CD process but we've run into the issue that our FE and BE codebases are in different repositories and we prefer not to stub every endpoint because that takes away some of the protection against breaking changes and takes a lot of time to stub everything.
Our last resort solution would be to host a separate environment solely for Cypress, but I was wondering if there's a better solution.