Gamma-ray light curve of 3C 279 (positionally associated with 4FGL J1256.1-0547) constructed from Fermi-LAT data using adaptive binning (Lott et al. 2012) with a constant relative uncertainty on flux of ∼15% in each bin. The vertical red dashed line indicates the epoch of RadioAstron observations on January 15, 2018, which coincides with the rising phase of a prominent short-duration (6.8 days) flare reaching a peak of 4.0 ⋅ 10⁻⁵ ph cm⁻² s⁻¹ (2.4 ⋅ 10⁻⁸ erg cm⁻² s⁻¹) on January 18, 2018.