To Activate Expire date feature you have to enable Two setting on inventory:

1. Lot/Serial Number

2. Expiration Dates

You will find those setting under Inventory-->Configurations-->Settings--> Traceability

There is two way to set up the expiration date of the product itself & on the Lot number.

1. Setting up the expiration date on the Product profile.

Products should be storable products and then go to the inventory tab

First set tracking to By Lots

Please set the value for the use time, life time, removal time & alert time:

If everything is set ok then after WH/IN validation lot expiration date will set up automatically 

Please click on Lot/Serial Number for checking 

Then You will be able to check expiration information

2. Editing Lots Expire Dates:
You also can create Lot Number in inventory-->Master Data-->Lots/Serials Number--> Create

then updates its expiration date information at any time.

To get report

Go to Inventory-->Master Data--> Lots/Serial Number then filter by Expiration Alert

Or Inventory Report Pivot View