To allow access to the area: From the entrance, try to go north and the guards will block you. Sayto the captain 'pass' and you will be teleported inside to buy an immigrant's pass. You can buy a temporary one for 10k or a permanent one for the following (the 50k is guaranteed a perm pass for all):
To allow trading: From the same square, go northeast to the ministry of commerce and give him 25k to get a trading license. This will allow you to enter/buy from shops in Xalt.