You only need to switch the 52’s mode from FM to DV, then tune in 433.900. Make sure you’re transmitting & receiving on the same frequency (simplex). Otherwise your radio doesn’t know it’s talking to a hotspot, it’s just using the default frequency in the Openspot, as any DStar radio could.
Now in what I just said, you could have the radio OR the Openspot switched in many different ways to make this fail. But if it doesn’t work, those are things you can read up on.