facebook pixel add below body
According to this answer here: https://www.facebook.com/help/community/question/?id=10200354561858276
you can place it inside the <BODY> element but FB recommends to keep it at the beginning of <BODY> or in the <HEAD> as the conversion will be then counted even if the page does not load fully or the user closes the page.
*** And facebook want to count it as conversion but if the user closes the page before it loads, from a real perspective this is not a conversion. This means that it should not be counted at all. I think that this conversion code should be put at the end of the body. Last possible tag