Hanjie Tan (Institute of Astronomy, National Central University), Mi Zhang, Guoyou Sun, Jingyuan Zhao (Xingming Observatory), Quanzhi Ye , Xing Gao (Xingming Observatory), report the outburst in a supernova candidate (17.96 r). The transient was discovered on several 120-s survey images (limiting mag about 19.0) taken by Xing Gao at Xingming Observatory #3 (N88) around Apr. 20.82238, 2021 UT using a unfiltered CCD (0.3-m f/3.6 reflector). Images can be found at: http://xjltp.china-vo.org/xm68ht.html
XM68HT C2021 04 20.82238 17 04 36.15 +30 52 31.9 17.96 r N88
