@jonbarthol this is basically correct. If you’re using OAuth to authenticate with the Contacts API, you’d need to log into HubSpot and authorize your account to get the initial access token and refresh token. Once you have the refresh token, you can use that to generate new access tokens when the access tokens expire.
If you’re working on a custom integration that’s only intended for your use, you could instead use an API key for your portal:
Also, if your visitors are filling out a form, you could also use the Forms API to send the relative marketing info to HubSpot.