Hmm there is currently no way for the user to select between different dice in the dice roll scene. You could event this beforehand via event commands (show choices -> do you want d4 or d20?) and then call a different dice roll based on that. You could then exit the scene and ask them what they want to roll next.
The rolling multiple dice at once is also not in the plugin yet, but it is planned for a future update.
Viewing post in [CGMZ] Dice for RPG Maker MZ comments
Hi, yes I provide support for all of my plugins, they should be easy to learn but if not you can reply here in the comments or if the issue is more complicated I recommend coming into my discord so it is easier to attach pictures and have quicker back & forth messages. All of my plugins also have a wiki page and online documentation.