Where do I find Discord IDs?
Enable developer mode and copy IDs via right-click — if you need them at all.
You usually don't need to — the wizard, sub-guild dialog and mapping dialog all pick servers, roles and channels from dropdowns.
But if you need an ID for support: enable Discord's developer mode under Settings → Advanced → Developer Mode. Right-clicking on any server, channel, role or user then shows „Copy ID".
A Discord ID is a 17–20-digit number like 782547639937269801.