The JsonHttpClient encapsulates a single instance of HttpClient, you would use it the same you would the HttpClient instance, i.e. share the same instance.
If you need different context properties just create separate instances. Having a few instances isn’t anywhere near the same as creating a new instance per request which is a common usage and pitfall for HttpClient. If the API designers wanted to mandate that you should only have 1 instance they would’ve made it a singleton (or have a singleton instance available) and not made it disposable.
You can inject the HttpClient instance in different JsonHttpClient instances if you really want to, but you should measure to determine it yields actual benefits before pre-maturely adopting the added code maintenance overhead.