How to get access to VisionPro cameras?

these forums are user helping other users like yourself, it's sort of going

to a physical apple store and asking other customers there advice

if it was me who wanted info about access of their API then I would try their developer forums

Apple Developer Forums

or reach out to their official support channels

Get Support (apple.com)

And or

Contact - Official Apple Support

And or

Contact - How to Contact Us - Apple

Visit an Apple Store close to your location. Buy Apple Vision - Apple

The Apple Stores are offering demos, where you can try out the Vision Pro. You have to reserve a time slot for your personal demo.

I hope the research project you want to join has sufficient funding, so you can purchase a Vision Pro. They are quite expensive - you are not just buying 3D glasses, you are buying a powerful spatial computer with many sensors, that you will be wearing on your face.