Plot[-(1-Exp[-t]),{t,0,3}, PlotStyle->{Black, Thick}, Ticks -> {{0},{0}}]

Plot[(1-Exp[-t]),{t,0,3}, PlotStyle->{Black, Thick}, Ticks -> {{0},{0}}]

Plot[(1-Exp[t]),{t,0,3}, PlotStyle->{Black, Thick}, Ticks -> {{0},{0}}]

Plot[(-1+Exp[t]),{t,0,3}, PlotStyle->{Black, Thick}, Ticks -> {{0},{0}}]