Open the App Store on your iPhone home screen. Use the Search button on the bottom left to search for "Alexa app" or a similar phrase..
Scroll through the results to find Amazon Alexa. Select the Blue cloud download button next to the app to download it
When the app is downloaded, select Open.
Since this is your first time using the app, you’ll be asked to log in with your Amazon account email and password. Input this information and select Sign-in.
Confirm your name and proceed. You have the option to set up a voice ID at this time, but you can always skip it and return to it later. When finished, choose Set up my features to implement some important Alexa settings, like your contacts for making calls, notifications, and so on. Choose Done when you’re ready.
You’ll now find yourself at the Alexa home screen, where you’ll see a number of options to link music accounts, add news or sports teams, make shopping lists, and so on.