cannot load awusbapi.dll

Having trouble loading the anywhere usb api dll in powershell. Here is the error.

Could not load file or assembly ‘file:///C:\Program Files\Digi\AnywhereUSB\Advanced\AwUsbApi.dll’ or one of its dependencies. The module was expected to contain an assembly manifest.

Can anyone provide some guidance on how to utilize the API? Documentation on it is lacking.