When using Electrode’s “Buzzap Generator” Ability, can I attach the 2 {L} Energy cards to Electrode before it is KO’d?
Yes, you can.
Source: Vivid Voltage FAQ (2020-10-31), TPCi Rules Team (2020-11-12)

Relevant cards

Note: All applicable cards may not be listed below.
SWSH4_46
SWSH4_46