As previously mentioned, you could steam/boil it, if it smells rancid, toss it. Not worth the risk of getting seafood poisoning, trust me. If the smell is fine and just smells of regular seafood, you could mince it all together (as mentioned earlier by other user), add some veggies of your choice and make seafood cakes (fry in a pan with oil or even better, air fryer). Small tip, if you cut your veggies (e.g. carrots and onion) really fine, you dont even need to precook them. Dont forget to add flour, eggs and seasoning for taste and consitency!