Looking at this discussion, there are several recommendations but the pattern is obvious - multiple users are pushing Parentaler (convenient since this is their forum).
Here’s the reality: Kids will find workarounds for any parental control within weeks. Most teens know about incognito mode, VPNs, and will just use friends’ devices or public WiFi to bypass restrictions. Your best bet is combining Google Family Link (free, built-in) with open conversations about what they’re seeing online - because blocking everything just makes them more curious and sneaky.