Can azure API Management service replace the authorization for Web API?

I'm completely new in APIM area, and need some advice and explanation. I have a public and unsecured at the moment Web Api. The Web api should accept requests from unknown number of external clients not associated with any identity provider. In this situation, is placing Api Management service between the client and the web api with the basic form of authentication (login and hashed password) possible in your opinion via APIM? For this filtering requests by IP. Generally I have to implement some form of authorization for my web api. Thanks in advance for hints.