If Type is set to Heat Flux, then the dialog will look as shown below.
Heat flux can be applied to curves and surfaces. When applied to curves, the value input becomes a nodal heat input. However, the units in the load definition will not change.
Heat flux loads may only be placed into a subcase when the analysis type is a heat transfer analysis (linear steady state heat transfer, nonlinear steady state heat transfer, or nonlinear transient heat transfer).
Time dependence only becomes active when the analysis type is set to nonlinear transient heat transfer.
Heat flux can have a variable load definition as well as custom display properties such as color, size, and density.