SPA pattern to support multiple backend versions

We have a Single Page Application SPA with Angular 5 and Spring Rest Backend.

the application is distributed and hosted by many customers each of them has a specific minor version of the software.

The Backend has not changed much in recent years, a breaking change every 2 month or so.

Now the problem we face, is that the client is evolving very fast but upgrading the backend is very expansive for the customer so we would like to install the client independent of the backend version. We would need to support multiple backend versions, what is a good approach to do that?

The idea is to use a list of adapters one for each minor version. Are there better approaches?