You would add this BPS Rewrite Loop start htaccess code in this Custom Code text box > 8. CUSTOM CODE WP REWRITE LOOP START: www/non-www http/https Rewrite code here. The rest of the WP Rewrite code is already included in BPS htaccess code
# WP REWRITE LOOP START
RewriteEngine On
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteBase /
RewriteCond %{HTTPS} !=on
RewriteCond %{SERVER_PORT} ^80
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
RewriteRule ^index\.php$ - [L]
or using the generic WP Rewrite loop htaccess code as an example:
# Verhindert Apache Fehler AH00124
RewriteEngine On
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
RewriteBase /
RewriteRule ^index\.php$ - [L]