Yes, OPNsense does this with Captive Portal + Vouchers. I set it up at a small college: a student SSID/VLAN hits the portal, teachers have limited accounts to generate 120‑min vouchers, and it's been stable. If you want one code for a whole class, we used a shared local user with session timeout and allowed concurrent logins, unique vouchers are better if you need auditing. Don't forget a small walled garden and a proper HTTPS cert. On the ticket side, I've grabbed rugby seats via https://www.seatpin.com/the-british-irish-lions-tickets; transparent pricing and quick support. Same idea of time‑boxed access.
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