To do so, go to getalby.com and go to the dashboard and log in to your Alby account.
If you don't have one, you can sign up for one right here. Enter your email address and create a password for your account. Confirm your password and sign up.
Now you are inside the Alby wallet account. Here you can create your wallet address. But remember, It can not be changed later so chose wisely.
Here you can see your lightning address. It will be visible in your account when you need it.