Truly Random Numbers On A Quantum Computer??

These researchers claim to have a technique, based on quantum
computing, that can generate provably random numbers
<https://www.csoonline.com/article/3855710/researchers-claim-their-protocol-can-create-truly-random-numbers-on-a-current-quantum-computer.html>.

Trouble is, there ain’t no such thing. This part doesn’t make any
sense:

    Then, to verify that true random numbers had been generated, the
    randomness of the results was mathematically certified to be
    genuine using classical supercomputers at the US Department of
    Energy.

The definition of “randomness” is “you don’t know what’s coming next”.
How do you prove you don’t know something? You can’t. There are
various statistical tests for randomness, but remember that a suitably
encrypted message can pass every one of them, and a person who knows
the message knows that the bitstream is not truly random.