Just an example for Debian 9.
1. Install ‘iptables-persistent’ package. Agree during installation the rules to be saved to /etc/iptables/rules.v4 .
2. Add rules (e.g. from console):
iptables -P OUTPUDT DROP
iptables -A OUTPUT -d 192.168.0.1 -j ACCEPT
3. Save rules:
netfilter-persistent save
4. Reboot and enjoy.
5. If you need to add/delete/edit rules, edit /etc/iptables/rules.v4 and then run ‘netfilter-persistent start’ to re-read the file.