You have to use Canon's AC power adapter and DC coupler (basically a "dummy" battery that plugs into the battery compartment) to power the T7 from the AC line.
(Canon CA-PS700 adapter and DR-E10 DC coupler)
Rodger
EOS 1DX M3, 1DX M2, 1DX, 5DS R, M6 Mark II, 1D M2, EOS 650 (film), many lenses, XF400 video
