how can I be qualified to have WLS
Look at the blue bar at the top of your screen - click on Resources, then click on "About Weight Loss Surgery" -- that should explain everything.
Then, check with your insurer to see if it covers WLS - and if you're employed, make sure your employer has not excluded it. I worked for a company that provide coverage from United Health, which did cover WLS - but my company put an exclusion for WLS to reduce costs, so I could not get the surgery. Now I have insurance that does cover it. Also note if your insurance does cover it, they may have additional requirements such as a six-month supervised diet, so read your policy carefully and call your insurer if you have any questions.
Good luck to you.
Your profile lists your BMI as 16, which would, if correct, make you underweight. How tall are you, and how much do you weigh?
Most insurance companies require a BMI of at least 40, or, if you have two or more co-morbidities (diabetes, high cholesterol, asthma, sleep apnea, GERD, arthritis, etc.) you can have a BMI as low as 35.