Why does link account doesn't appear in fc mobile setting

Hi 5dk1bd956fa4​, 

Do you remember what Date of Birth you popped in when setting up the FCM account? 

The link option may not appear if the FCM account is under 18 years of age.

Underage accounts are restricted from connecting to social networks, accessing social features, and using features that might not be appropriate for them.

- EA_Lanna