Call Transfer Problem

Hello i am new to freepbx and it seems that i have problems forwarding calls. By default, the in-call attended transfer is *2 and i did not make any changes to it. However, when i press *2 on the phone, there is no prompt for me to dial the extension.Every other functions like joining conference calls and dialing between extension using the same phone is working and i could not figure out the problem. Please help me with this problem.
Thank You