Function reference
There are two functions, and they answer two different questions.
BIFROST.LEDGER
What is the number?
Returns one aggregated value — a balance, a movement, a budget figure.
BIFROST.ENTRIES
What is it made of?
Returns the individual transactions behind that value, as a spill range.
Why only two
The first argument is always the name of a formula your organisation has defined in the portal, and that name is what decides which data source is used. So a balance, a budget figure and a supplier balance are all BIFROST.LEDGER — they differ by which formula you name, not by which function you call.
Your available formula names, and the parameters each one takes, are listed under Formulas in the portal. They are specific to your organisation, which is why this page cannot list them.
Getting help
If a cell shows a message instead of a number, the support page lists what each one means and what to do about it.