Hello gankhadka39,
Did any of the suggestions in my reply to your other post (Seller Portal → Account Status & Registration) help you locate one of the buttons you can click to start the application process?
If these buttons are not visible, please contact the Seller Portal team to find out why they are not appearing in your account: From Seller Portal, click Help → Contact us. Then, click Contact us at the Customer Center located near the bottom of the page (if a pop-up with “Did you mean samsung.com?” appears, close the pop-up).