"It's important to note that this fallacy should not be used to dismiss the claims of experts, or scientific consensus. Appeals to authority are not valid arguments, but nor is it reasonable to disregard the claims of experts who have a demonstrated depth of knowledge unless one has a similar level of understanding and/or access to empirical evidence." - https://yourlogicalfallacyis.com/appeal-to-authority
Appeal to authority is NOT an appeal to majority/popularity, which definition is what I linked to. "Scientific consensus" is an appeal to popularity/majority.