Navigate to Site Features and enable the Prayer Requests feature. In Site Builder, select "Submit Prayer Request" in the Add Feature dropdown. It will then be added into your menu.
When a user clicks on this feature in the menu, they will submit a request that will be submitted to the e-mail address that you have listed in your Site Preferences under Prayer Request Email. You can have one or more address listed in this field. You can also allow these people access to View Prayer Requests in Permission Administration so that they can review the requests from your website.
To set the email address for where prayer requests are sent visit:
Site Preferences > General