If you have the conditions, you can go to the gym and ask the coach to give you guidance on leg strength training, such as squat, squat and so on.
If you don't have the conditions, you can also do some training at home or outdoors, such as squats and leapfrog.
The strength of the waist and abdomen is also very important. You can do sit-ups for this.
Of course, the strength of the upper limbs is equally important. Better go to the gym. If not, you can use dumbbells to train yourself, such as lifting your shoulders sideways.
Physical training is also necessary, and can be exercised through long-distance running.
In fact, you should also see that badminton is a comprehensive sport, both aerobic and anaerobic. Therefore, it is not a one-off event to practice badminton well, but it needs persistent efforts to get it.