FIRE6: Feynman Integral REduction with Modular Arithmetic

FIRE is a program performing reduction of Feynman integrals to master integrals. The C++ version of FIRE was presented in 2014. There have been multiple changes and upgrades since then including the possibility to use multiple computers for one reduction task and to perform reduction with modular arithmetic. The goal of this paper is to present the current version of FIRE.