A Discord ID looks like a set of 18-19 digits (for example: 646059759296053250). To get it, you need to:

1. Open User Settings (gear icon next to your nickname in the bottom left)
2. Go to the section:
   • on desktop — Developer Mode
   • on mobile — Advanced Settings
3. Enable Developer Mode
4. Click on your avatar in the bottom left
5. In the profile menu, click "Copy User ID"
6. Paste the copied ID into the field below