Update INSTALLATION.md

INSTALLATION.md

@@ -9,7 +9,37 @@ To install it, simply double click on the installer and follow the step by step
 
 Download the latest MacOS Installer (Universal - Intel and Apple Silicon) from here - Link
 
-You can refer to the video given below which shows the steps to run API Dash on your macOS device.
+**As this app is distributed outside the App Store you have to follow the following instructions to setup and run it only for the first time.**
+
+You can refer to the video given below which shows the steps to install and run API Dash on macOS.
+
+https://user-images.githubusercontent.com/1382619/227956871-87376f18-d80f-4a53-9456-cb724f8149c7.mp4
+
+
+##
+
+
+**Step 1** - After downloading `api_dash_macos.dmg` file, right click & open it.  
+Note: If you directly open it by double clicking, macOS will warn you and not allow you to open it. So, right click and open it again.
+
+**Step 2** - Click Open in the dialog box
+
+**Step 3** - Drag and drop API Dash App in the Applications folder as shown in the video
+
+**Step 4** - Now go to the Applications folder
+
+Note: The next step has to be performed twice so that macOS adds the app to whitelist
+
+**Step 5** - Right click on API Dash App & click Open
+
+**Step 6** - Click OK
+
+**Step 7** - Once again right click on API Dash App & then click on Open
+
+**Step 8** - Now in this new dialog box click on Open to launch the API Dash App
+
+**Step 9** - The application is now ready for use 
+
+**Step 10** - This process has to be followed only once and from the next time you can directly launch the API Dash App from the Launchpad.
 
 
-Step 1 -