Crafting can be accessed through [Menu] > [Crafting], where you can view and select items by category.

When you select an item to craft, the required materials and costs will be displayed, and you can proceed with crafting.

For equipment items of 3 stars or higher, crafting results are classified as ‘Success,’ ‘Great Success,’ or ‘Ultimate Success.’
Equipment crafted with ‘Ultimate Success’ will have performance superior to the options of the equipment attempted.
 
※ The probability of crafting results can be checked at the bottom under ‘Probability Information.