This the default newsletter popup provided by the theme. The available settings are:
Show in customizer -- used to show the popup within the customize area so you can update the content while you see it.
Enable Newsletter banner -- will enable the banner for all users
Show newsletter after -- period set in seconds after which to show the popup
Logo, Logo width and Logo width - Mobile -- these are settings which provides you with the ability to add your own logo within the popup to make it more branded
Subheading, Heading and Body text -- used to control the textual content
Image -- the image shown on desktop and mobile
Image - Mobile -- this image will be shown on mobile instead of the main one
Image position -- predefined options for Right, Left and Top
Newsletter form code -- this can be used for embed forms like Klaviyo, Mailchimp, etc.