useApiUrl

import { useCustom, useApiUrl } from "@refinedev/core";  
  
interface PostUniqueCheckResponse {  
  isAvailable: boolean;  
}  
  
const apiUrl = useApiUrl();  
  
const { data, isLoading } = useCustom<PostUniqueCheckResponse>({  
  url: `${apiUrl}/posts-unique-check`,  
  method: "get",  
  config: {  
    query: {  
      title: "Foo bar",  
    },  
  },  
});  

export const App: React.FC = () => {  
    return (  
        <Refine  
            dataProvider={{  
                default: dataProvider("<https://api.fake-rest.refine.dev/">),  
                other: dataProvider("<https://other-api.fake-rest.refine.dev/">),  
            }}  
        >  
            {/* ... */}  
        </Refine>  
    );  
};  
  
const apiUrl = useApiUrl("other");  
//    ^ <https://other-api.fake-rest.refine.dev/>  

   import { Refine } from "@refinedev/core";
   import dataProvider from "@refinedev/simple-rest";

   const API_URL = "<https://api.fake-rest.refine.dev";>

   export default function App() {
     return (
       <Refine dataProvider={dataProvider(API_URL)}>
         {/* Your components go here */}
       </Refine>
     );
   }

   import { useCustom, useApiUrl } from "@refinedev/core";  

   interface PostUniqueCheckResponse {  
     isAvailable: boolean;  
   }  

   const MyComponent: React.FC = () => {
     const apiUrl = useApiUrl();  

     const { data, isLoading } = useCustom<PostUniqueCheckResponse>({  
       url: `${apiUrl}/posts-unique-check`,  
       method: "get",  
       config: {  
         query: {  
           title: "Foo bar",  
         },  
       },  
     });  

     if (isLoading) {
       return <div>Loading...</div>;
     }

     return (
       <div>
         {data?.isAvailable ? "Title is available" : "Title is not available"}
       </div>
     );
   };

   export default MyComponent;

   import { Refine } from "@refinedev/core";
   import dataProvider from "@refinedev/simple-rest";

   export const App: React.FC = () => {  
     return (  
       <Refine  
         dataProvider={{  
           default: dataProvider("<https://api.fake-rest.refine.dev/">),  
           other: dataProvider("<https://other-api.fake-rest.refine.dev/">),  
         }}  
       >  
         {/* Your components go here */}
       </Refine>  
     );  
   };  

   const apiUrl = useApiUrl("other");  
   //    ^ <https://other-api.fake-rest.refine.dev/>