Is it possible to manually transfer calls to a speed dial (90-99)? This is from a IX-12KTD-3... Thanks in advance

I see there is a 'transfer off-premise' option but the user wanted to use speed dial.

You can't transfer directly to a speed dial bin.

You CAN, however:

Transfer to an extension which is forwarded to a speed dial bin with Flexible Call Forwarding;

Create an external feature code (access number) which routes to whatever number you want.

Another option (for an individual call) is:
Press TRAN
Dial line access code (i.e. '9')
Press SPEED and dial bin number (or use a one-touch speed dial key programmed on a telephone)
Hang Up.

Outside caller is then transferred to the number programmed in the speed dial bin (unsupervised conference)