You can use your Instagram account to automatically share posts or reels to Threads.
To automatically share Instagram posts to Threads, update the Instagram app and enable sharing to Threads in the Share To section.
To automatically share Instagram reels to Threads, record or select a reel, enable sharing to Threads in the Share to section, and tap the Share button.
If you're unable to share Instagram content to Threads, ensure that both the Instagram and Threads apps are updated, check account restrictions, regional availability, and internet connectivity.