You can target specific platform versions for your application by using the "runtime" property in the app.json file. This property allows you to define the minimum allowed platform version that your application can be installed on. The "runtime" value is set using a standard major/minor structure, like this:

Setting the "runtime" property also controls features that you are allowed to use in the AL Language extension, as not all features are supported on all platform versions. 

When you publish a Business Central application, the verification is done to make sure that the "runtime" version specified in the application is compatible with the actual version of the platform. If it is not, then you will get an error similar to the following one:

The runtime version of the extension package is currently set to '3.0'. The runtime version must be set to '2.3' or earlier in the app.json file in order to install the extension package on this platform.