Should I use a User access token or a System User access token when configuring the Instagram channel?

You must use either a User access token or a System User access token when connecting your Instagram account to your Conversation API app. If your Instagram account is part of your business portfolio in the Meta Business Manager, you must connect your account using the System User access token option. If your account is not part of a business portfolio , use the User access token option.

Learn more about the Sinch Messenger API for Instagram.