Warrky USB C to HDMI Cable 4K 60Hz[Anti-Interference, Gold-Plated Plugs] Aluminum HDR Type-C to HDMI 2.0 Cord, Thunderbolt 3/4/5 Compatible for iPhone 16/17 Series, MacBook Neo, iPad Pro, Galaxy-6ft

Did I say connect USB to the projector? I said, use a USB-C to HDMI adapter. Connect HDMI from the adapter to the projector. Bluetooth is a audio format, not a video format. USB allows for data transfer, not video transfer. A adapter like this...https://www.amazon.com/WARRKY-USB-C-HDMI-Cable-Anti-Interference/dp/B087213LB3/ref=sr_1_11 One end goes into your iPhone (assuming USB-C) and the other end is HDMI and it plugs into the projector. That's all you need to do for screen mirroring. There are TONS of YouTube videos out there about connecting a iPhone to a TV, and your projector is a TV, but in a different format.