To upload your contacts from your iPhone or Android mobile app:
1. Click on menu button.
2. Press Friends tab.
3. Now click Contacts > Get Started (button).
Once you’ve turned on mobile contacts for uploading, your contacts list will automatically be uploaded to Facebook profile, when you open your mobile app.
If you want to upload your contacts from other accounts (just like as email):
1. Visit the friend requests Facebook page.
2. Below “Add Personal Contacts, Now choose the type of account you’d like to upload your contacts from
3. Now enter the required information, then click “Find Friends” tab.