Basic license of Hard Disk Manager 16 does NOT require Serial Number to be entered.
You activate it as soon as you log into your account through the software interface.
You only need to enter a Coupon Code if you purchased one to get all Advanced features. If you’re fine with features of the Basic license, you only need to activate the Basic license by logging in into your account in the program.
Upon entering the purchased Coupon, in-app Tabs will change from FREE to Advanced and from this moment Hard Disk Manager 16 Advanced has been fully unlocked and activated.