Within LEO, go to "HR Stuff" at the top of the interface. Click that and then you'll find a "My Benefits" section. This will take you to Zenefts where you'll be able to request PTO, review balances and also manage any of your other employee benefits.
Alternatively, you can simply visit www.zenefits.com.
As always, talk to your Consultant Success Specialist if you have any issues or log a request in the support area of LEO.