[Kwant] Staggered Sublattice Potential

Respected Sir, I want to include the staggered sublattice potential in Kwant. The problem is, it is an onsite term which takes positive and negative values to two different sublattices of Graphene. how will I include this onsite potential? For reference you can check the fourth term on right hand side of equation (1) in the paper given in the following link. https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.95.146802. Thanks a lot. Sayan Mondal, IIT Guwahati, Guwahati, India https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.95.146802. https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.95.146802.