Apologies for this basic question. My excuse is that it's my first cmsms site

I am setting up a form using Form Builder and have added one extra field in the form in addition to those there by default. Problem is that this new field doesn't show up on the email.
I have checked the documentation and found this:
If you're missing fields in an email that gets generated, check the disposition field's template, and make sure you're specifying the missing fields. Seems obvious, but it's an easy mistake to make.
But it's 2am and I have no idea where the disposition field's template is.
I have checked the 'advanced settings' tab on the new field (it's a telephone number by the way) but no luck there.
ANy help would really be appreciated.
Thanks