If your powerpack only has one 8pin connector you can get a molex like the one in the picture below, also just make sure the power pack can deliver the exact watts needed for the GPU and motherboard to run perfectly
https://i.imgur.com/60okg81.jpgNEVER use this at any GPU.
High risk of permanent failure.
AMD GPUs can use just one 6 or 8 pins connectors.
My 2080 only works (and still mining)if both are connected.
