Hi TharakeshA,
Correct that FormIt for Windows is currently the only FormIt platform that supports modifying Dynamo object parameters directly.
We're exploring how we can better integrate FormIt and Dynamo - including supporting other platforms like Web - for future releases.
Note that despite not being able to change input parameters, if you load a file with Dynamo objects in FormIt Web, the geometry will show up as expected and can be manually modified as with other objects.