Once your contact list is created and saved, you will be taken to the Contact List page where all the Contact Lists that you have created would be listed.
Against each of the Contact List, there is an Edit button and View Details button. Click on the View Details button, and you will be taken to the Contact List details page. On the top right side, you will see a button "Email List Widget." Click the button, and you will see Email List Subscription Page URL, button widget, and page widget. Pick any of the widgets as per your preference.