Code for numerical simulations in Kwant of tight-binding model discussed in paper arXiv:2207.10066 "Breathing mode in open-orbit magnetotransport: a magnetic lens with a quantum mechanical focal length". The presented Jupyter notebook contains all the code and data for plots and code to generate plots presented in the manuscript. Main calculation principles: 1) For the wave function distribution inside scattering region the code internally matches incoming plane waves from the infinite leads with the solutions inside scattering region (which is finite in both directions). 2)For the conductance calculation - the code calculates the full S-matrix for each mode injected from the infinite lead (contact) on the left to each of outgoing leads (main on the right and other drains that play a role of fully absorbing boundary conditions). From this S-matrix the transmission is calculated, which gives dimensionless conductance.