Hi Priya,

When adding a User Task to the Forms process diagram, in the General tab of options you can check the box to "Allow Direct Approval" (see attached image). This will allow for direct approval from the "Details" pane of the Tasks list. To allow for direct approval using e-mail, you will need to specify an e-mail approval server in the Forms configuration page, and if applicable configure the approval server with any necessary filters, routing rules, etc.

Hope this helps!