Labs for AP must be done in pen.
They must be a record of the steps performed, and of the data collected as the lab is performed. The notebook is the place for all information from the lab as it happens. A lab book is your proof that the lab occurred as you said it did. Nothing has greater credibility than contemporaneous notes.
Try to be organized, but do not take separate notes elsewhere and then "tidy it up" for your audience. We love the great science that you do "warts and all".
It is a small step from "tidying up" data to wholesale "whitewashing" data. This is a temptation that has cost several researchers their jobs and reputations over the last couple of years. Scientific misconduct
Sample of lab data: