Add These to TeeWorlds:

Add in;
InfClass Mod (found here )
The ability to upload maps

You should already be able to upload new maps using FTP.

For your mod, it seems very old so I guess based on version 0.6 of teeworlds and I want to migrate to 0.7 as older version are vulnerable to DDoS attacks.

But how can I upload new maps, can you tell me the steps to do?

When you have created your server, you should have a FTP server + login on your control panel, use those with an ftp client to upload your maps