Set SSIS Package parameters in SQL Agent

Hello,

I have defined two package parameters in my 2014 SSIS package

1. ssas_backup_dir

2. ssas_instance

I would like to set them through the "Set Values" tab in a sql agent job. I know variables can be set as below

These are not variables, but package parameters. I have tried many different variations trying to set the parameters but keep getting errors unable to set the parameter. 

DTExec: Could not set .......

Any ideas on how to set the project parameters in the set values tab in sql agent?

Thx