That was the outer lens, not the internal lens. If you broke the internal lens you’re kinda screwed at this point as there are no great options for replacing it.
Surprisingly I found the lens replacement on GoPro’s site.
[https://shop.gopro.com/accessories-3/lens-replacement-kit-for-hero-session/ARLRK-002.html|Lens Replacement Kit]
[https://www.youtube.com/watch?v=Lm7RDdcTVVA|Lens Replacement Video]