ref below using Designer:
if u have deployed using custom (visual studio)
The purpose of this post is to demonstrate how to deploy one or more SharePoint designer workflows, enable for web browser rendering and associate with a list all through custom code tied to the feature activated event of a web feature.
Yes, marking your feature to use the following assembly will automatically register the workflow and InfoPath form for web rendering, but this post is purely to show how to do it yourself and add additional functionality.
assembly = “Microsoft.SharePoint, Version=126.96.36.199, Culture=neutral, PublicKeyToken=71e9bce111e9429c”
class = “Microsoft.SharePoint.Workflow.SPDeclarativeWorkflowProvisioningFeatureReceiver”
I know it’s possible to use the above feature receiver and add your custom code to another feature that depends on the first one, but this is just another way of doing it and at the very least demonstrates how you can enable forms for web rendering