Maintaining backward compatibility in Service Oriented Architecture on client side

I am in a situation where my application will get updated from the app store or play store but the APIs that the apps are using wouldn't be updated.

So, the scenario is that the client is at an updated version (e.g. 2.0) and the APIs are not (e.g. 1.0).

In this case, I need to find a pattern in which the client at the updated version can still access and use APIs of older version.

Can anyone please propose a solution for the same.

Note: My apps are built in iOS and Android respectively.

P.S.: I cannot force update the APIs.