Add sales channels in advanced pricing options

See the default sales channel already linked in advanced pricing options and add more sales channels with the select sales channel option.

1. In pricing, under advanced pricing options, a default sales channel is already linked.

   ✓ 2026년 10월 15일에 제품에서 확인됨

2. Additional sales channels are added using the select sales channel option, which shows existing sales channel entries and a dropdown to add more.

   ✓ 2026년 10월 15일에 제품에서 확인됨