You mean add your signature, right? In Journey 2, it seems that only the bound 8 1+ green clothes will have signatures, and the bound equipment cannot be traded, only signatures can be added.

Among the equipment forgers in the city, three first-class silver or three first-class hard covers can be added to the signature;

Similarly, if you want to modify the signature, you should also look for a forger of Wangcheng equipment. The grade and quantity of materials required are different.