I pasted the script into Header and Footer scripts like you said and saved changes. Nothing has gone into header.php either in the parent or the child theme. Maybe it’s the code? It starts:
<!– Facebook Pixel Code –>
<script>
!function(f,b,e,v,n,t,s)
{if(f.fbq)return;n=f.fbq=function(){n.callMethod?
The code is supposed to go into the child theme, right?