Hello, in my case, I am using in the "To" field:

#user.{Variable.applicant}.email#

Where 'applicant' is actually a workflow variable that contains a username. This is because I need to send a communication to a specific user and not a group.

In case it is the whole group to which the notification should be sent, I do not use a Tool, but I use the "User Notification" plugin in a global way for the whole app.

I'll go and try that ! Thank you very much

I think that also instead of the 'Variable.applicant' statement if a hash variable is used, it should work. In fact it may also work for a group if you use, for example, the varable hash assignee. Review: Hash Variable

Hi Camilo A. García, how did you use the hash variable to email to a specific person? Because it's not working for me. 

I used field_proj because that's the ID for the requestor in my system. Thanks in advance

In my case is worwing with: #user.{variable.solicitante}.email# Could it be just the capital letter? I dont know. Is the variable "field_proj" declared as a workflow variable from the process diagram? And is it well loaded and related in the forms?

I did everything, not capital letter, declared as workflow variable from the process diagram as well as in the form and map participants to user. But still not working. Really need help for this.