feat: updated use method in rokt kit

Author: Jaissica Hora

src/Rokt-Kit.js

@@ -242,6 +242,25 @@ var constructor = function () {
         return self.launcher.selectPlacements(selectPlacementsOptions);
     }
 
+    /**
+     * Enables optional Integration Launcher extensions before selecting placements
+     * @see https://docs.rokt.com/developers/integration-guides/web/library/integration-launcher/#use
+     * @param {string} extensionName - Name of the extension to enable
+     * @returns {Promise<*>} A Promise resolving to the extension API if available
+     */
+    function use(extensionName) {
+        if (!isKitReady()) {
+            console.error('Rokt Kit: Not initialized');
+            return Promise.reject(new Error('Rokt Kit: Not initialized'));
+        }
+        if (!extensionName || typeof extensionName !== 'string') {
+            return Promise.reject(
+                new Error('Rokt Kit: Invalid extension name')
+            );
+        }
+        return self.launcher.use(extensionName);
+    }
+
     /**
      * Sets extension data for Rokt Web SDK
      * @param {Object} partnerExtensionData - The extension data object containing:
@@ -375,6 +394,7 @@ var constructor = function () {
     // Called by the mParticle Rokt Manager
     this.selectPlacements = selectPlacements;
     this.hashAttributes = hashAttributes;
+    this.use = use;
 
     // Kit Callback Methods
     this.init = initForwarder;