I forgot how to get another tab......any help?

for which one equipment or Inventory I do but

Inventory not for equipment, just go to it then there is the purchase tab it does cost gold.

But for equipment (the one that can full more quickly is to switch to equipment than purchase new tab.

Thanks. But I dont see the one for regular stuff. I have 2 tabs already

If you're just referring to your inventory, there's a "Purchase Tab" button below your inventory box

it's the same for both. --'