Hi Jim,
I am also a resident of Europe (EU), but as a law rule we only have requirements that someone mark something before sending a message, but they don't have to write anything extra. I know different EU countries have their quirks, but I have see a example to suggest something.
Yes, In Form Builder addon you can add extra input field where people can manually write/type " I agree privacy policy etc." But HTML field is not needed for that sentence. Or create your own checkbox fields.
(!) Contact addon has limited features, so you won't be able to add extra field(s).