What to use instead of Calor 340 cylinder for portable BBQ gas?

Just bought myself one of these portable BBQs: https://appliances.calor.co.uk/outdoor-living/gas-bbqs-accessories/calor-mini-bbq.html

But per the description, the Calor gas cylinders that fit inside the BBQ are no longer avalable in UK. I know absolutely nothing about gas types, other than what my Alpkit stove uses. I understand I can use the larger Calor gas cylinders (“Patio Gas”), but would really prefer to use the smaller, almost hairspray-can sized ones, so that the whole unit is self contained.

Gas adaptor looks like below photo. Can I use MAPP gas or similar, or is there an adaptor that would let me use more readily available gas cylinders (that are still small enough to fit inside)? Other ideas?

A bit of a Google suggests these should fit the reg…

https://www.screwfix.com/p/rothenberger-propane-disposable-gas-cylinder-400g/71092?tc=EA6&ds_kid=92700055262507126&gclsrc=aw.ds&ds_rl=1244066&gclid=EAIaIQobChMIp-H8vau76gIVrIBQBh0mZgXlEAQYBSABEgKeVvD_BwE

The Calor Gas 340 has now been discontinued by Calor Gas and this Primus 2000 Sievert 2000 is the identical replacement so you can continue to use your existing equipment. Next time you can buy just the 2000 refill cylinder.

Or just change the regulator to one with a similar output but for easily available cylinders.

Could maybe use these with the correct regulator?

Weber disposable gas canister

Interestingly I tried to find info about the cavagna type 798 regulator and there’s an astonishing lack of info out there.
TBH I’d consider changing it to a commonly used regulator (with cheap cylinders that you can get anywhere) with an output pressure of 28 – 37mbar.
I run Weber Q BBQs on 28mbar and a two burner camping stove on 37mbar – anything around those numbers will be probably be fine.

Edit:
For example one of these regulators (30mbar) for £5 and these canisters that can be bought properly cheap (smaller than the original but they’re half the price by volume!)

This is all super helpful – thanks! I’ve ordered one of the regulators from @sharkbait ‘s link – thanks!