Can I use material icons for free?

Excuse me, I'm a developer working on a new financial application involving cryptocurrency, and I'm wondering about the usage of material icons. I've seen numerous applications utilize these icons effectively, and I'm curious if I can incorporate them into my project without incurring any costs. Specifically, I'm interested in knowing if there are any licensing requirements or royalties associated with using material icons, or if they're freely available for commercial use. Could you please clarify the legality and cost implications of utilizing material icons in my application? Thank you for your time and assistance.