There’s a number of ways in which you can drain your kitchen sinks into a grease interceptor.  One could use a low profile grease interceptor where the inlet is low enough to connect to.  One could partially or fully bury a regular grease interceptor to meet the inverts.

These pictures are of what NOT to do:  raising your sink up with metal rods zap strapped to the legs is not an approved method.  It’s a matter of time before this fails and if fully loaded with water; will weight hundreds of pounds.  This could seriously injure someone.

Please hire certified plumbers to do your installation, ask for their license, insurance and copy of plumbing permit.