I think the manufacturer of that keyboard (known under several brands) made their own keycaps. Similar keycaps are not available elsewhere AFAIK.
There are replacement keycaps for Logitech's keyboards with Kailh Choc (branded as "Logitech GL") but Logitech has a flatter keycap profile and some modifier keys are the wrong size.
Kailh's own and third-party keycaps for Kailh Choc have all been smaller than regular size, and are mostly used on DIY ergonomic keyboards with smaller key spacing. Kailh's have a weird uniform 0.5u staggering also, so they won't fit.