It looks like you're referring to some of the integrations listed at the top of the page in that screenshot, like Zoom. Some of those are special partner integrations on Dropbox, not built like third party apps linked using the Dropbox API, and so will not show up in linked app list returned by the API.
Thanks a lot for replying, So you mean Zoom, Slack, Gmail, Outlook, Microsoft Teams all these are special partner Integrations apps? but they get listed on UI dropbox console under connected apps and like Zoom is having write permission to the dropbox account to upload zoom meeting files so we want information about those kind of apps as well. Is there any way we can list those special partner integration apps?