You are going to visit St. Petersburg only and for up to 8 days
Starting from October 1, 2019, nationals of 53 foreign States may be granted an e-visa to enter the Russian Federation through air, naval, automobile, and pedestrian checkpoints located in the territory of Saint Petersburg and the Leningrad region. E-visa is valid for eight days staring 00:00 of arrival day. Check the possibility on the Russian Foreign Affair Office web-page