How to add dimensions in FlexUnits

General Usage
1

I would like to add a dimension (say, for example, Money) in FlexUnits, and define a base unit for it (say EUR).
I have searched in the doc and online, but I can’t seem to find how to do that. Could someone point me to a tutorial?

In case it clarifies what I am trying to do, here is what I am using with Unitful:

module MyUnits
using Unitful
@dimension MU "MU" MonetaryUnit false
@refunit EUR "EUR" Euro MU true
end
Unitful.register(MyUnits)
using .MyUnits

# I can then do things like
cu = 1u"EUR/L"
c = cu * 10u"m^3"  |> u"kEUR"