Vue Apollo doesn't pass the variables

I'm trying to query user information, but Vue Apollo doesn't read the variables I pass.

Here is the query:

export const USER_QUERY = gql`
  query ($input: UsernameInput!) {
    userInfo(input: $input) {
      ...
    }
  }
`;

Here is the query in the component, currently I pass static value instead reading it from the route params.

 apollo: {
    userInfo: USER_QUERY,
    variables() {
      return {
        input: { username: "johndoe" },
      };
    },
  },

Inside the network tab there are no variables: