Help with Workflow to include subform attachment

Help with Workflow to include subform attachment

I have a Form Release_Drawing and another form Drawing_Files

Drawing_Files has a file upload field named File_Upload

I am using the Drawing_Files as a subform in Release_Drawing form.
The name of the subform is Drawing_Subform

The user typically fills out details in the Release Drawing form, along with uploading file in the Subform's File_Upload field.

I am trying to create a workflow which will send email with the subform's file as an attachment. The workflow will be executed whenever the user chooses "yes" in the Send_Email dropdown field present in the subform.

Here is the code, but it is not working. Requesting help.
I am using it in Release Drawing > Created > Addition of row in Drawing Subform

for each row in Drawing_Subform
{
if row.Send_Email = "Yes"
{
sendmail
[
from :zoho.adminuserid
to :zoho.adminuserid
subject :"A New Drawings has been Released"
message :"<div>Find the Drawing attached</div>"
Attachments :file:input.row.File_upload
]
}
}


Thanks in advance.