RHEL as a router

Good Evening,
I am trying to configure RHEL 8 as a router. I have one interface facing the Internet with static IP address assigned (eth_ext) and one inteface (also static IP) facing LAN (eth_int). I set net.ipv4.ip_forward = 1 and made the following:

firewall-cmd --direct --add-rule ipv4 nat POSTROUTING 0 -o eth_ext -j MASQUERADE
firewall-cmd --direct --add-rule ipv4 filter FORWARD 0 -i eth_int -o eth_ext -j ACCEPT
firewall-cmd --direct --add-rule ipv4 filter FORWARD 0 -i eth_ext -o eth_int -m state --state RELATED,ESTABLISHED -j ACCEPT

I still can't access the internet from the second machine (that has only one nic connected to the same lan)