What Should I Do If My X-ray Suggests Pulmonary Tuberculosis Left Upper Lobe?

Good morning. My xray says Consider PTB left upper lobe. But I don t have the symptoms and such. Also, I consulted to our medical center. They say that I should done a sputum test. But the problem is I don t have a phlegm, I try my best to spit some but don t have still. What should I do?