What burns more fat Cardio or strength training?

You burn fat when you consume fewer calories than your body needs to maintain weight. Neither cardio nor weight training default to burning fat...if it did, people who exercise regularly and maintain would just wither away. Cardio is good for your cardiovascular health. Weigh training is important for maintaining and building lean mass and bone density among other things.

Assuming you're keeping an energy deficit:

In the short-term, cardio. I can easily burn a thousand or more calories on a long bike ride, a substantial fraction of which will came from fat oxidation. It's technically possible, thought unlikely you'll hit that same burn with weight training.

In the long-term, likely weight training. Muscle uses far more energy at rest than fat does, so if you increase your muscle mass through resistance training, you'll be burning more calories 24/7. Additionally, you improve your nutrient partitioning (how much energy you use from fat versus from carbohydrate) with improved body composition, so for the same energy expenditure you'll generally use more fat.

Anecdotally, when I was a flabby 180 lbs many years ago, I worked out my BMR to be around 1400 cals/day. Now, at a fairly muscular 140 lbs, my BMR is around 1800 cals/day. If I hadn't put on a decent amount of muscle, I couldn't have gotten substantially smaller and still increased my resting energy expenditure.

Pretty cool, but the results require patience and consistency. Cardio is still a great tool for fat loss, but you should find a form you enjoy. If you hate the treadmill, walk/run outside, or take up biking, or swimming, or hiking, jump rope, martial arts, etc. It should be something you like to do.