Please send this link to your iPhone/iPad through SMS or existing email or type it manually in Safari browser.
Once you open above link, you will see below screen, please click on install button
Please accept the warning message and click on "Install" button again to proceed.
Please enter your full email address here.
Please enter your Email address again as username.
Please enter your password (usually it is the same as your computer login password)
You will see below screen, which will setup your email address.
Finally, you will see the confirmation, please click on "Done" button to finish.