Аннотация:MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB 210419A ( S. Laha et al., GCN 29828) errorbox 58845 sec after notice time and 58929 sec after trigger time at 2021-04-19 23:15:50 UT, with upper limit up to 18.1 mag. Observations started at twilight. The observations began at zenith distance = 43 deg. The sun altitude is -14.8 deg. The galactic latitude b = -31 deg., longitude l = 275 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1595763 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_______________ ______|_____|_______|______|______ __ 59019 | MASTER-OAFA | C | 180 | 17.9 | 59305 | MASTER-OAFA | C | 180 | 18.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.