i'm trying to take the knob off the dresser i made and copy it onto another object i made. the dresser and new object are two different files

i've tried to select the knob as an element and copy/pasting it into the new object which failed

i've tried to Import -> Merge the objects together but it failed

i'm not sure if i'm doing something wrong or i'm missing a step. can anyone help me out?

this is the knob:






this is the new object:









please / thank you!