Here's what you can do with it:
* Unlock the Silph Co. Building: This is the primary use of the Key Card. You'll find it in the hands of the security guard at the main entrance of the building. By using the Key Card, you can unlock the doors and enter the Silph Co. building.
* Advance the story: You need to enter the Silph Co. building to continue the main story. You'll confront the villain, Giovanni, there and recover a very important item for the story.
Here's how to use the Key Card:
1. Obtain the Key Card: It's found with the security guard at the Silph Co. entrance.
2. Talk to the Key Card reader: There are special Key Card readers in the Silph Co. building. Talk to these readers to access areas they unlock.
3. The Key Card will work automatically: You don't need to do anything extra once you talk to the Key Card reader. It will automatically unlock the doors and allow you to proceed.
Let me know if you have any other questions about the Silph Co. or the Key Card!