Noted.
Try to replace it with this:
# php -- BEGIN cPanel-generated handler, do not edit
# Set the “ea-php73” package as the default “PHP” programming language.
<IfModule mime_module>
AddHandler application/x-httpd-ea-php73 .php .php7 .phtml
</IfModule>
# php -- END cPanel-generated handler, do not edit
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
RewriteRule ^ https://%1%{REQUEST_URI} [R=301,L]
</IfModule>
#Insecure Content
RewriteOptions inherit
RewriteEngine on
Header set content-Security-Policy: upgrade-insecure-requests
If something goes wrong just switch it back to your previous content.
Let us know if that helped though.