From FMWebschool Reference

Mac OSX Manual Connection: Step 2

Now make sure FileMaker Pro is open and idle. This means exit any FileMaker Pro dialogs and simply leave a database open. Make sure you have no file open, manage database, and other dialogs open.

Now click the "Manual Connection" button on the FMTouch screen. Enter the IP address of your Mac from the previous step, and the FileMaker Pro client should prompt you to allow or deny the connection.

If at this stage you are not connected, please post on the FMTouch forum and we will help you troubleshoot the problem:

FMTouch Users Forum