Email notifications about form submissions are sent by the form's Send email action. To check it, click Marketing → Forms & landing pages, click the form, click Edit form, then Settings and the Form actions tab. See Form settings for the steps with screenshots.
Check the recipients
Each Send email action lists the addresses it sends to. Click the action to change them in the To field. If the form has no Send email action, click Add more actions and add one.
A recipient can also be a tag (text in {{ }}). The email then goes to the address the tag gives for that submission. If the tag has no value, no email is sent to it.
Fields missing from the email
The email lists the form's fields, and the list is updated when you change the form. If a field is still missing, delete the Send email action and add it again. A new action's email lists all the form's current fields. Note the recipients and any text you added to the email first, since you need to enter them again.