C# code needs to run in IEC61131-3 program

Please excuse my ignorance.
The brochures make mention of ‚The patented task handling allows any combination of IEC 61131-3 code, high-level languages, and model-based tools in one task‘. Am i correct in saying that the C# code needs to be ran from within PLCnext Engineer as a part of a task? So i can’t run independent C# application on the runtime? It would need to run natively on the Linux OS and therefore there isn’t any library support from PLCnext in this scenario?