To disperse some of the hype here around using this for "uncrackable" key exchange: QKD has been a product of choice for cybersecurity conmen for decades.

https://www.nsa.gov/Cybersecurity/Quantum-Key-Distribution-Q...

https://www.ncsc.gov.uk/whitepaper/quantum-security-technolo...

https://en.wikipedia.org/wiki/Snake_oil_(cryptography)

Stick with TLS. If you really think quantum computers are a threat to anything, use a hybrid-PQC key exchange.

My honest professional opinion is a cryptographically-relevant quantum computer will never exist, making classic cryptography superior in every case.