This has nothing to do with your webpage dashboard. To add the banner to your site at all, you used a shortcode that looked something like
[jsbrotate ... /].
To adjust the default options, you need to add parameters to this. To set the length of time (in seconds) you want each banner to display, you use the
[jsbrotate imgdisp=12 /] will display each image for 12 seconds (rather than the default of 8 seconds.
This parameter is in addition to the
images= parameter you use to list your image URLs.
You can read more about shortcodes and how they work in the Codex, but this is really all the help I can give you at this point.