How to block, mark as spam, or unblock phone numbers on Samsung devices

Samsung Galaxy S8+ Samsung Galaxy S8+
Samsung Galaxy S8 Samsung Galaxy S8
Samsung Galaxy J3 (2017) Samsung Galaxy J3 (2017)
Samsung Galaxy J5 (2017) Samsung Galaxy J5 (2017)
Samsung Galaxy J7 (2017) Samsung Galaxy J7 (2017)
Samsung Galaxy J7 Pro Samsung Galaxy J7 Pro
Samsung Galaxy J7 Max Samsung Galaxy J7 Max