https://www.engadget.com/figma-is-now-free-for-all-us-school-students-105514037.html
Educators can sign up for access through Figma's website..
Eh this is the same strategy adobe used. Get them into your ecosystem early, that way there is an entire generation who comes in demanding figma as their tool of choice.
If I could recommend them anything it'd be to skip Figma and use penpot instead. Same features and everything, but open-source and no lock-in ecosystem.
Having used both, Penpot still had a feature gap. For example, prototyping in Figma is much farther along. Penpot is still stuck in Invision land.