Addon Istallation Problem in sap b1 9.0.......

Dear Experts....

I am Working on one test implementation project, we needs to register the add-on on SAP B1 9.0.'

I am not able to register the Add-on. and their is no folder "Add-on" in C:Program Files\ SAP \ SAP Business One\...

Kindly Request you to guide me.

Thanks in Advance....