That’s the embedded generation section which is the bottom third of my post City of Johannesburg 2024/2025 rates - #4 by fredhen.
TLDR:
You need to go through the process @Bobster went through to register. COJ and SSEG registration
You then need to move to the Domestic TOU tariff which has a crazy capacity charge per month (compared to domestic prepaid).
You get a flat rate of 94.68c/kWh for feeding back (~R1.09/kWh including).
You need to be a net consumer so take more kWh than what you give back.