But some sort of check must be done? How often? Thanks
FAR 61.58 requires that the PIC of an airplane requiring more than one crewmember or is turbojet powered must have had a PIC proficiency check within the preceding 12 calendar months and in the type concerned within the preceding 24 months. This can be accomplished in a simulator or airplane. A proficiency check contains the same checking elements as a type ride and must be administered by a "person authorized by the administrator". In the airplane that usually means a DPE.
In the USA, only a tiny and ever diminishing proportion of all training and checking events for such aircraft are accomplished in the airplane these days. It's pretty much limited to types with no sim, experimentals and some small operators with small jets and limited resources. The vast majority of bizjet operators do their training and checking at the sim center. Perhaps the greatest arbiter of aviation risk mitigation is the insurance underwriters!