**Step-3:** Upload your **_iOS_** application (.ipa file) or **_android_** application (.apk file) to the LambdaTest servers using our **REST API**. You need to provide your **Username** and **AccessKey** in the format `Username:AccessKey` in the **cURL** command for authentication. Make sure to add the path of the **appFile** in the cURL request. Here is an example cURL request to upload your app using our REST API: