how to hide next button of player till user not watch slide 100%

Have a look at this thread.

Control HTML5 video output in captivate 9?

You should need to create your own buttons for navigation, you can then time the Next button to appear after the video on the timeline.

Unfortunately this is not possible.

Unlike Articulate Storyline, Adobe Captivate doesn't provide a way to manipulate the visibility of the buttons on the skin playbars.  You can only turn the entire playbar ON or Off by manipulating the cpCmndShowPlaybar System Variable (setting it to 0 turns off the playbar).