How do you add spin up and spin down fermions to a FermiHubbardModel class in Qiskit?

Question

I've been programming a FermiHubbardModel class with the Qiskit library for a VQE, but the class only shows input options for the U (onsite) and t (hopping) parameters when I construct a LineLattice.

I've tried to manipulate the lattice with the parameters Qiskit offers, but no attempts have been successful.

Is there a way to add fermions to the FermiHubbardModel class? My code is below.

import numpy as np
from qiskit_nature.problems.second_quantization.lattice import LineLattice, FermiHubbardModel

L = LineLattice(6,onsite_parameter=4,edge_parameter=1)

L.draw()
hamiltonian = FermiHubbardModel(L,4).second_q_ops(display_format='dense')
op = JordanWignerMapper().map(hamiltonian)