Block websites using Mikrotik router

First I need to create some reg expressions.

To block one site I can use:

^.+(izismile.com).*$

To block multiple sites I can use:

^.+(facebook.com|youtube.com).*$

So I create this expression in Layer7 section:

Now I note down what is my actual local network:

Hands on. Create new firewall rule:

Select forward chain and write down your address scope.
I can write 192.168.99.1/24 but it will be converted to 192.168.99.0/24:

Scroll down a lot till the section Filter appears.
Select Later7 protocol: name of layer7 rule:

Scroll down till bottom. Select action drop:

Scroll to the top of page and click [Save]:

Now move the rule before any other forward Accept rule!

No need to restart anything. Everything works instantly :)