12vhpwr to 2, 8pin pcie

I got an A850GN and 3080 suprim, the problem is the psu only have a single pcie 8pin and a 600w 12v cable. It’s not a modular psu so Im planning to use a extension cable to slit the 600w to 2 pcie 8pin connectors with a $20 cable on amazon. What are you guys thought on this.