I've used a good selection since the original RX10 was released in 2013: HVL-F20M, HVL-F32M, HVL-F43M, Nissin i40, Godox TT350S & TT685S.
The F20M isn't powerful enough to use other than indoors as a trigger for other Sony (etc.) flashes.
The F32M doesn't have anything to recommend it over the TT350S which is a fraction of the price.
The F43M is a keeper but pricy.
The i40 is nearly very good but the dials rotate a little too easily and the hinge is placed too far to the rear so the whole thing isn't flat when the flash is pointing up which makes it a pain in the shoulder bag.
The Godoxen are great value and work very well.
If I'm out I take either the TT350S or F43M depending on whether I know I'll need flash or not. If I'm at home I'll use a scattering of Godox units with an XPro-S transmitter.
Basically, if you're not a heavy flash user, get a TT350S or the Lithium-battery V350S. Otherwise get a TT685S or V860S II.