Free tools work great for traffic. What’s the best way to convert users into paying users after? I have tried a lot of things for my side project like limited

Free tools work great for traffic. What’s the best way to convert users into paying users after? I have tried a lot of things for my side project like limited generations of the output and then putting a signup requirement if you want to use the tool more often but people are simply not converting to the main solution. Link to free tool: https://www.hackathon.camp/free-tools/hackathon-certificate-generator https://www.hackathon.camp/free-tools/hackathon-certificate-...