In Safari 26.4, it support WebTransport now https://developer.apple.com/documentation/safari-release-notes/safari-26_4-release-notes

Congratulations on being selected to attend WWDC at Apple Park and on winning the 2024 Swift Student Challenge 🎉 For your U.S. non‑immigrant visa and invitation letter (including guardian information for your mother, if needed), please contact Apple Developer Support directly via email. They can assist with issuing a formal invitation letter for visa purposes.