Аннотация:MASTER-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) was pointed to the Swift GRB210419.98 (trigger No 1044236,14h 11m 50.40s , +36d 00m 34.6s, R=0.05) errorbox 11774 sec after trigger time at 2021-04-20 02:44:03 UT, with upper limit up to 18.3 mag. The observations began at zenith distance = 19 deg. The sun altitude is -43.4 deg. The galactic latitude b = 70 deg., longitude l = 64 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1596583 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_______________ ______|_____|_______|______|______ __ 11805 | MASTER-IAC | C | 60 | 17.5 | 12698 | MASTER-IAC | C | 180 | 18.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.