  The electronic properties of junctions defined electrostatically on twisted
bilayer graphene can be addressed theoretically using lattice models. Recent
works have introduced minimal local orbital models to describe twisted bilayer
graphene at the magic angle (MATBLG) with different degrees of approximation
and accounting for fragile topology. In the present work we use a Green's
function formalism to obtain the spectral and transport properties for MATBLG
junctions based on these models. We introduce different symmetry breaking
perturbations to simulate the effect of interactions and characterize the
topology of the bulk bands by analyzing the corresponding Wilson loops. We then
analyze the spectral properties for different types of edges and in the case of
a domain wall in the sublattice symmetry breaking parameter. We further
consider a three region junction where one could control independently the
central and lateral regions doping level. In the limit where the central region
is fixed at the charge neutrality point and the lateral ones are heavily doped,
the spectral and the two terminal transport properties can be understood in
terms of the hybridization of chiral states along the junctions. These
properties are found to be extremely sensitive to the orientation of the
junctions along the moir\'e lattice.
