increase the time between the sliders

this plugin, in which file should I tinker to increase the time between a slide and another because I read that it should enter the code “pausetime: 3000” in the header, when I insert and some had no effect the only code that the plugin asks for put is “<php if (function_exists (‘show_nivo_slider’)) {show_nivo_slider ();}?” where the banner will be inserted

I thank the help

https://wordpress.org/plugins/wp-nivo-slider/