As @trappmartin says, you need to define a transformation from unconstrained to constrained, but in this case that’s just going to be the identity operation, so you only the need additional bit of code:
Bijectors.bijector(d::Determin) = Identity{0}() # <= `0` indicates 0-dimensional, i.e. univariate
and you’ll be able to use HMC and NUTS:)