i enabled the shops from l2.ini
[PrimeShop]
UsePrimeShop=true
UseClassicPrimeShop=true
UseGoodsInventory=true
NewPrimeShop=true
added the item in list xml
<item id="57" cat="1" paymentType="0" price="150" panelType="3" recommended="0" startSale="315558000" endSale="2127452400" dayOfWeek="127" startHour="0" startMinute="0" stopHour="23" stopMinute="59" stock="-1" maxStock="-1" salePercent="0" minLevel="0" maxLevel="0" minBirthday="0" maxBirthday="0" restrictionDay="0" availableCount="0">
<item itemId="57" count="1" />
</item>
productname in system too.
ProductName-eu.dat
product_name_begin id=57 outer_name=[test] description=[description test] icon=[BranchSys.icon.br_four_leaf_clover_box_i00] icon_panel=[None] mainsubject=[] product_name_end