PerfDog's software is currently unable to offer entrants different fees for junior handlers in hunt test levels and FT stakes. If your club wants to offer a discounted entry fee to junior handlers, you will need to handle the refund manually through your club (by refunding the difference with a club check or otherwise). Folks should enter their dog as usual through PerfDog and note that the handler will be a junior handler in the 'Secretary notes' while they're entering their dog.
Suggestions:
If you want to add a reminder for folks while they're entering, you can add a note to each level, such as "Include I'm a junior handler in the notes field when you enter."
To do this, go to Setup > Stakes and add the note you want entrants to see in the 'Notes' box. Read more here: Add notes for entrants about the stakes
You can include this language or something similar in your Premium List near your junior handler entry information:
“For online entries, include ‘I’m a junior handler’ in the notes field when you enter. You will receive a refund from the club for the amount of your junior handler discount after entries close and the secretary confirms your junior status.”