curl Errors: Status code: 403 Response: {"correlationId":"08e80949-4eeb-4f00-b6cd-f1df0da55f24","message":"This hapikey (my hapikey) does not have proper permissions! (requires any of [content-access])","requestId":"f2e1bb0b-98dc-4606-ae03-55e5aa2327ae","status":"error"}
The 403 error you're seeing here most commonly appears if you don't have access to the tool you're trying to use the API for. Does the portal you're using have access to blog tools? If not, then this request will always return an error.
Whether you have access to blog posting via API depends on whether you can post to blogs using the in-app interface. If you go to your navigation and can select Marketing > Website > Blog, you have blog access. If any part of this path is locked or unavailable, you don't have blog access, which means that you can't post a blog post via API either.
The fact that Website isn't showing up in your menu means that you don't have access to any of our web-hosting features, which includes blogs. You can only do via API what you can do within your account itself. Because you don't have a paid account, you can't host blogs on HubSpot, and thus can't post to a blog via API.