What to do when some component models are not found in ADS?

Hi,i have problems of using ADS;
1. if some component is not found,what should I do.for example some HBT transistor
2.is there any library that contains specifically Varactor diodes.

Thanks in advance for answering these questions.

u need to import the models to ADS
or use specific design kit

about the varactors , i didn't find . so i created the model of my varactor

khouly