The competitor to CarbonAds you are referring to is probably CodeFund. We ran CodeFund for almost 4 years. Even though we shut it down, we left the code open source (https://github.com/gitcoinco/code_fund_ads). Please feel free to use whatever you want from the project. Also, you might want to watch the video demonstrating how the project worked here: https://berry.sh/codefund-demo/
Good luck! It's a wild ride you are embarking on!
[1]