How to force a factory reset or hard reset on Nokia devices

Nokia 6.1 Plus (Nokia X6) Nokia 6.1 Plus (Nokia X6)
Nokia 5.1 Plus (Nokia X5) Nokia 5.1 Plus (Nokia X5)
Nokia 5.1 Nokia 5.1
Nokia 3.1 Nokia 3.1
Nokia 2.1 Nokia 2.1
Nokia 8 Sirocco Nokia 8 Sirocco
Nokia 7 plus Nokia 7 plus
Nokia 6.1 Nokia 6.1
Nokia 1 Nokia 1
Nokia 2 Nokia 2
Nokia 7 Nokia 7
Nokia 8 Nokia 8
Nokia X Nokia X
Nokia X+ Nokia X+
Nokia XL Nokia XL
Nokia X2 Dual SIM Nokia X2 Dual SIM
Nokia N1 Nokia N1
Nokia 6 Nokia 6
Nokia 5 Nokia 5
Nokia 3 Nokia 3