You'll need the right Dentally license to access developer settings. Might need an upgrade before you can get access. Thanks

Minimum is the "advanced" plan

Thanks for this, had taken a look at the advanced vs standard - what is the difference between limited and full API access? Can I only work with the marketplace integrations already made or can I use something custom as well?

I've been building my own API integrations and it needed the Advanced plan for this. I assume limited will be the marketplace / pre made integrations with vendors already completed