In the email subject use:
[webform_submission:values:YOUR_FIELD_KEY]
.
If you don't want a label to appear, you need to add :no_label[webform_submission:values:YOUR_FIELD_KEY:no_label]
- If the value is a field in a fieldset, use
[webform_submission:values:YOUR_FIELDSET_FORM_KEY:YOUR_FIELD_KEY]
.
(For more details, look at the webform tokens)
In the Email handler's custom Twig template:
- {{ data.YOUR_FIELD_KEY }}