Installing the FM Books connector plug-in on a Terminal Server is slightly different from the standard installation method. You'll need to install the plug-in and the QB Bridge separately. Let's start with the plug-in.
Log into the server with an Administrator account (or have the credentials handy for an Administrator-level account) and perform the installation of the plug-in just as you would on a single client machine. As you run through the installer, you will come upon a page that asks you where you would like to install the plug-in. You will want to change this path to the Extensions path of the FileMaker version your users will be running within the Program Files or Program Files (x86) directory. For example, if you are running FileMaker 19, the installation path should be:
C:\Program Files\FileMaker\FileMaker 19\Extensions
The rest of installation will be the same as installing for a normal Client machine.
Once the plug-in is installed, extract out the "Install QB Bridge" zip file from the Extras folder in the download package and run the installer "Install QB Bridge.msi".
Again, when the installer asks for where to install the plug-in, change the directory to the directory below and ensure the "For Everyone" option is chosen where it asks who to install the QB Bridge for. If you are unable to navigate to the path with the "Browse" button, you can type the path into the file name field to force the installer to bring you to the path.
Complete the installer as normal.
Now you will need to test registration and communication with your QB company file. Open the demo file from the desktop "FM Books Connector Extras" folder in FileMaker and confirm that the plug-in is loading. You should see the version number in the demo file, as well as receive a splash screen when starting up if you haven't registered in Live mode before.
Using the Demo license, register the plug-in and confirm that the Operating Mode field changes to "DEMO".
Open QuickBooks and open up a sample company file. Once the company file is fully loaded, in the FM Books Connector demo file, click "Test Connection". You may need to configure the connection information in QuickBooks. Confirm that the QuickBooks information field populates appropriately. This confirms that the plug-in is fully installed and able to communicate with QuickBooks.
Repeat the demo file connection test with a second user account on the terminal server. You do NOT need to run any installation on this second user account; the first account already handled all the installation. If everything was installed and configured correctly, then the connection test on the second account should successfully regiser the plug-in and establish a connection to QuickBooks.