1 pointUse a TE Timer and activate it with a positive transition.
1 pointDid you look at the Help file? The example is for an older PLC, but the basics are the same. When you place the Timer HMI element on the screen, link to the timer operand you want, check the Preset box, and the Keypad Entry box. Also, set up the Format and other niceties for your HMI element. That's all there is.