Jasa_89 wrote:I have my own small server, where plays 3 people.

One of them bought an apartment at Scron, And then deleted his character. So where I can get the key that deleted with his character?
AFAIk, you have two options, DM Intervention/abilities or server admin intervention.
As a DM, you could create and apply the necessary updates to a key so that it would open the apartment door.
Or, as the server admin you could copy the necessary archetype from the original map to another players inventory or add it back into the map.
Either method is not that complicated, just tedious to perform.
For those wondering, the map in question is: /scorn/taverns/apartments
Jasa_89 wrote:
And I'd like to know also: that what should I do when I have money to buy the apartment #10 (If I remember correctly) couse it's bigger that the small ones. And I own a small apartment key. Can I sell it back somehow? Couse I'd like to release that apartment for other people.
The only way to sell the key is to find another player and to exchange the key and money that way. There is now way to "reset" that apartment for another player to purchase it.
You've discovered why these apartments were replaced with the permanent apartments in later versions. Players greatly outnumbered the available storage areas (aka apartments) and everyone ran into problems like you describe.
The Permanent Apartments in Scorn are located a few spaces north of the City Hall, SW of the Port Gate, etc.