[tryingToLearn (top answer)] What worked for me was adding wildchar '*'. Although for production builds, I am going to be more specific with the value of this field. But for dev purposes you can do this. Setting available under, keycloak admin console -> Realm_Name -> Cients -> Client_Name. EDIT: DO NOT DO THIS IN PRODUCTION. Doing so creates a large security flaw.

Context: Stack Overflow #45352880 (top answer, 128 votes, 33 answers): I am trying to hit an endpoint from my API to authenticate a user from Keycloak, but it's giving me error Invalid parameter: redirect_uri on the Keycloak page. I have created my own realm apart from master. Keycloak is running on HTTP.