On a phone, the front camera sits at the top of the screen and your script sits below it. Read the script and you are looking slightly down; look at the lens and you cannot read. The distance is small, and viewers notice it anyway.
Put the current line as close to the lens as the layout allows, and make the text large. A larger line means fewer eye movements per sentence, and fewer movements is what reads as eye contact.
Prop the phone further away if you can. At arm’s length the angle between the lens and the text is a few degrees; at thirty centimetres it is much more. This is the single biggest improvement most people can make, and it costs nothing.