Add apiService

frontend/src/services/ApiService.jsx

@@ -0,0 +1,17 @@
+export async function api(url) {
+    const response = await fetch(url);
+    if (response.ok) {
+      const jsonValue = await response.json();
+      return Promise.resolve(jsonValue);
+    } else {
+      return Promise.reject('Response was not OK.');
+    }
+  }
+
+export async function getSession(sessionId) {
+    return await api(`/api/sessions/${sessionId}/`); 
+  }
+
+  export async function getSessionList() {
+    return await api(`/api/sessions/`); 
+  }