Getting your bell rung is an idiom about taking a blow to the head. "To receive a violent blow or injury, especially to the head and as might stun, concuss, or incapacitate."
Since it's an idiom, Lupin Red can't literally get his bell rung. But the audio foley team gave the attack an incredibly present ringing sound (and a bell ringing sound, at that). So despite his head not actually being a bell, it did in fact ring.
(Though it's interesting to note that Toei didn't take any chances with that shot; they never even show Destra's hammer making contact with Lupin Red's head. Instead they rely heavily on visual FX and audio to sell the blow)
No.
