Why isn't the email field included in the email notification?

Mi formulario https://www.jotform.com/build/51484050601849/settings/emails#preview   tiene un detalle, al enviar el correo  para enviar el acuse, el campo de correo electrónico se muestra vacío.. como puedo corregirlo.

To clarify, do you want to include the text element to show in your email content?

You would have to edit your autoresponder's email content and add the text manually.

Guide:https://www.jotform.com/help/430-How-to-Edit-the-Email-Template-for-Notifications-and-Autoresponders

Please give it a try and let us know if this fits your requirements.

In the notification email, the email that the client captured at the time of filling is not shown.

Thank you for explaining the issue further. It seems there is an issue with the fields in your current notification/autoresponder email.

Can you please try to create a new autoresponder/notification email ?

https://www.jotform.com/help/25-Setting-up-Email-Notifications

https://www.jotform.com/help/26-Setting-up-an-Autoresponder-Email

Please give it a try and let us know if the issue still remains.

I receive the email notification correctly and whoever completes the form also receives it correctly.

The problem is that the notification that comes to me in the email field is not displayed and since I have to return information to that same email I need it to be visible. to be able to copy and send what he requested.

It seems the field "Correo electronico" is not showing in your email content.

The issue could be with the form field, creating a new notification email should refresh such field and show the values.

https://www.jotform.com/help/25-Setting-up-Email-Notifications

Please try creating a new notification email and let us know if the field value is still missing.

In the form I only have one notification email and one more reply, when trying to load another notification tells me the system that I must change to a paid account. If I delete the one I have, it will allow me to add it again to my free account.

I have been checking your form and was able to see the issue, what happens is that the wrong field name is included on the email, I would recommend you to copy the field name from the field settings: 

Then paste the copied name on the email template replacing the string that is highlighted on this screenshot: 

I hope this helps.