Dispatch is not returning a promise using redux-thunk with typescript

I'm actually migrating some code to typescript so I'm new in all this type stuff. When I used redux-thunk with regular javascript the dispatch method returned a promise that helped me to handle errors and stuff. The action was this one:

export const login = ({email, password}) => {
    return async function (dispatch) {
        try {
            const result = await api.post(`/auth/login`, {username, password});
            return dispatch({type: 'set_user_session', payload: result.data});
        } catch (err) {
            throw (err.response && err.response.data) || {code: err};
        }
    };
};

Then I called normally using the useDispatch hook:

const dispatch = useDispatch();
...
dispatch(login({username: "admin", password: "adminpassword1"}))
    .then(d => console.log("ok"))
    .catch(err => console.log(err));

Now that I migrated the code to typescript, the action now looks like this:

export const login = ({username, password}: Credentials): ThunkAction<Promise<Action>, {}, {}, AnyAction> => {
    // Invoke API
    return async (dispatch: ThunkDispatch<{}, {}, AnyAction>): Promise<Action> => {
        try {
            const result = await api.post(`/auth/login`, {username, password});
            return dispatch({type: 'set_user_session', payload: result.data});
        } catch (err) {
            console.log(err);
            throw (err.response && err.response.data) || {code: err};
        }
    }
}

This is executed without problems, but if I try to handle this:

dispatch(login({username: "admin", password: "adminpassword1"}))
    .then(d => console.log("ok"))
    .catch(err => console.log(err));

I get this error:

TS2339: Property 'then' does not exist on type 'ThunkAction   >, {}, {}, AnyAction>'

I tried to read the section about types in Redux but I cannot find the correct way to declare this dispatch function to work as I need it.

https://redux.js.org/recipes/usage-with-typescript

What's worse is that I'm getting this runtime error after the action is execute:

Possible Unhandled Promise Rejection (id: 0):

So the promise is somewhere.