rooting - How to run a firewall and an AdBlocker on a non-rooted phone at the same time?

I have a non-rooted Android phone and would like to use both a Firewall and an Adblocker at the same time. How can I do this?

I could only find Firewalls and Adblockers for non-rooted phones that use use VPN with only one VPN connection being allowed.