Does the Proton VPN iOS app route all DNS queries through the tunnel, and ultimately to their DNS servers, on both cellular and Wi-Fi?

I figure WiFi will for but I only have a very basic understanding of how cellular data works and I am pretty new to the privacy conscious networking game. So maybe this is a stupid ass question but I’d appreciate any insight!

P.S. this is my first real post into the fediverse! Be gentle.