How do i make a locked door

[pcmastergamer]

I want to make like a ladder but i want to have the section locked to where the player needs a key to open the door to get to the ladder D: but i dont know how to do that can someone tell me how btw the area at the bottom with the iron bars around it is the ladder area so I want the door that is locked stoping the player from getting in the iron bars until he has a key

 

[CT_Bolt]

I want to make like a ladder but i want to have the section locked to where the player needs a key to open the door to get to the ladder D: but i don't know how to do that can someone tell me how btw the area at the bottom with the iron bars around it is the ladder area so I want the door that is locked stopping the player from getting in the iron bars until he has a key

You need something like this?

Spoiler: Map Screen

Spoiler: Event Setup

If you wan't to take the key away once used, you remove the item on page 2.

Let me know if this helps.