What do you mean by the luminous flux of a spotlight?

Generally speaking, luminous flux is the synthesis of the amount of light emitted by the illuminant per second.
From:SEEPOSH—Connie
Generally speaking, luminous flux is the synthesis of the amount of light emitted by the illuminant per second. Unit: lumen (LM), indicating the amount of light emitted by the illuminant. The more light emitted, the greater the lumen value.
Test method: integrating sphere test.