A 6-digit key is a security key which allows you to send and receive files.

When you select the file to be sent and tap Send, a 6-digit key will be generated.

It is a one-time key that can be used just for 10 minutes. If the other party enters the key in the key field to receive for Send Anywhere, the file is transferred.

Somehow you need to tell the other party the 6 digit key. Otherwise, tap ios_link Share button on the top right of the screen. You’ll get a link that is valid for 48 hours, instead of a 6-digit key.