Content-Security-Policy in htaccess

I'm using wordpress with nicepage.
I want to secure my webpage as much as possible.

but when adding content-security-policy to my .htaccess file, almost nothing works in the plugin, and the site isn't showing my page normal.

Can you help me how I can include nicepage plugin as exception for my security?

this is what I've added to my .htaccess file:

Header set Content-Security-Policy "default-src 'none'; script-src 'self'; connect-src 'self'; img-src 'self'; style-src 'self'; frame-ancestors 'none';"

greetings

maarten