To lose 1 kg of fat per week, ie 4 kg of pure fat per month, you should do some exercise that burns approximately 600 calories a day, 5 times a week, in addition to daily bodybuilding. See how many pounds you need to lose weight in: How to know how many pounds I need to lose weight
To achieve the desired caloric burn, you should perform the exercise for 1 hour and keep the heart rate within the ideal, which should be approximately 80% of its maximum capacity. This ability, however, will depend on your fitness, age, and intensity of exercise. Exercising below these values will not help you lose weight but may bring other health benefits, such as improving cardio respiratory fitness.