Facebook and Instagram are owned by the same company.
To link accounts on a mobile device:
- Tap on the three lines at the top of the right corner in Instagram
- Tap Settings and Privacy
- Tap on Accounts Center
- Tap on ADD accounts and follow the on-screen instructions.
If you want to post photos or videos simultaneously on social media platforms from other platforms such as Twitter, you need an online social media tool such as Hootsuite or Tailwind