In the equilibrium ${\mathrm{NH}}_4{\mathrm{HS}}_{\left(\mathrm{s}\right)}\iff {\mathrm{NH}}_{3\left(\mathrm{g}\right)}+{\mathrm{H}}_2{\mathrm{S}}_{\left(\mathrm{g}\right)}$. The forward reaction is favoured by

Adding some more NH₄HS

Removing some NH₃ from the reaction mixture

Adding some more H₂S

Adding some more NH₃