For both creating a manual or automatic list, you will need to navigate to the Advanced Tab > Data > Opt-In List in your form configurations.
For automatically adding contacts to an opt-in list, select the list you want them to be added to from the Available List drop-down and click ADD.
The list will now appear below.
Note: you can add multiple lists for contacts to be added to. If you are automatically adding the contacts, contacts will be added to all the lists.
If you would like your contacts to manually add themselves to opt-in lists, you would repeat all of the steps laid out above, however, once you have added the list to the form, click on Auto listed under the Type column, this will change the type to manual
Note: the manual options provide an extra confirmation that the contact would like to be submitted to the opt-in list and if multiple lists are available, they can choose which one they want to be added to instead of being added to all of them.
If you have added multiple lists, you will be able to reorder how the contact will see them on the form under the actions column. Click Down or Up to move the list.
Note: the Up and Down option will only appear if multiple lists have been added.
Once you have your lists added and in the order you want them to appear, you will have to add them to the form section you want them to appear in.
Navigate to the Layout Tab and create a new field under the section you want the list selection to appear
You will need to name the field and create the field
Note: Do not worry about the Type drop-down as you will have to change this within the advanced settings of the field.
To display the lists in this field section, click on the pencil icon to manage the field.
Use the Type drop-down to change the type of field to Email Opt-In List.
When you view your form online, you will now see checkboxes with the Opt-In lists you created previously.