shows the "set a currency" prompt when a currencied expense has no base

Hello! I’m @splitsheetbot, here to help you split bills with friends.
I use something called a Splitsheet—a dynamic message that keeps track of all expenses and debts. Below, you’ll find your first Splitsheet.

Here’s how to get started:
1. Join the Splitsheet by clicking the 👥⁠➕ button (or reply with add @​username)
2. Reply to the Splitsheet with a description of your expense
3. Pin the Splitsheet for quick access

Examples of messages:
- groceries 50 (sender paid, and the cost is split evenly among all members)
- bought coffee for Emma 15 (sender paid, and only Emma owes)
- John bought concert tickets for me and Sarah, 40 each (John spent 80, and both Sarah and you owe)

How to edit expenses:
- Edit your own message
- Reply to your message with the changes
- Reply to your message requesting deletion

Adding expenses is free. One payment shows who owes whom, for the whole group, forever.

When you're ready to start a new Splitsheet, use the /newsplit command. You can mention members to add them immediately: /newsplit @​alice @​bob
If you have any questions or suggestions, feel free to contact @splitsheet_help_bot