how to craft item +5??

If you meet all requirements make sure the items are not equipped. Its annoying but you have to unequip the items to make them. That includes make sure its out of formations with the item and favorites

You need a lot of materials to make it to +5. Don't forget the weapon books material to awaken it to lvl 50.

The one item you are missing is the recipe itself.

Ras Algethi "Recipe" ---> "Missing Item"
Ras Algethi lvl 10 x2
Material Required

Most recipes can either be bought at one of the shops with different currencies or by farming.

Craft +1 using x2 level 1 +0
then craft +2 using x2 level 10 +1
then craft +3 using x3 level 20 +2
etc etc total 63 recipe, million gil and all materials. Must be level 0 to make +1, must be unequipped and it will appear.