You will need to have someone to complete a webform and when they submit that webform, a new lead will be created or updated. To provide them with the webform, go to the Answering Service app in your Back Office Workspace and click on the little wrench from the top-left of the screen and select "Webform"

After that, you will have on the right side of the screen "Shareable Link" and that's the webform they will be completing and submitting when it's done.