我无法在输入中输入任何信息。输入部分是空白的，但当我输入时什么也没有出现。它们之前是可以工作的，而且我没有对任何代码进行任何更改。当我能够输入数据时，我无法将数据发布到后端。我一直收到错误“POST 500（内部服务器错误）”。

const Properties = props =>{
    const [property,setProperty] = useState({
        street : '',
        town : '',
        area : '',
        PostCode : '',
        NoBeds : '',
        NoBath : '',
        NoLivingRooms : '',
    })
    const [properties,setProperties] = useState ([]);
    const [message,setMessage] = useState(null);
    const authContext = useContext(AuthContext);

    useEffect(()=>{
        PropertyService.getProperties().then(data =>{
            setProperties(data.properties);
        });
    },[]);

    const onSubmit = e =>{
        e.preventDefault();
        PropertyService.postProperty(property).then(data =>{
            const {message } = data;
            resetForm();
            if(!message.msgError){
                PropertyService.getProperties().then(getData =>{
                    setProperties(getData.properties);
                    setMessage(message);
                });
            }
            else if(message.msgBody === "UnAuthorized"){
                setMessage(message);
                authContext.setUser({username : ""});
                authContext.setIsAuthenticated(false);
            }
            else{
                setMessage(message);
            }
        },[]);
    }
     
    const onChange = e =>{
        setProperty({...property,[e.target.street] : e.target.value})
    }

    const resetForm = ()=>{
        setProperty({
        street : '',
        town : '',
        area : '',
        PostCode : '',
        NoBeds : '',
        NoBath : '',
        NoLivingRooms : '',
        });
    }

    return(
        <div>
            <ul className="">
                {
                    properties.map((property) =>{
                        return <PropertyItem key={property._id} 
            property={property} 
            street={property.street}
            town={property.town}
            area={property.area}
            PostCode={property.PostCode}
            NoBeds={property.NoBeds}
            NoBath={property.NoBath}
            NoLivingRooms={property.NoLivingRooms}
            />
                    },[])
                }
            </ul>
            <br/>
            <form onSubmit={onSubmit}>
                <label htmlFor="street">Street Name</label>
                <input type="text" 
                       name="Street name" 
                       value={property.street}
                       onChange={onChange}
                       className=""
                       placeholder="street name"/>
                <label htmlFor="town">Town</label>
                <input type="text" 
                       name="town" 
                       value={property.town}
                       onChange={onChange}
                       className=""
                       placeholder="town"/>
                <label htmlFor="area">Area</label>
                <input type="text" 
                       name="area" 
                        value={property.area}
                       onChange={onChange}
                       className=""
                       placeholder="area"/>
                <label htmlFor="postcode">Postcode</label>
                <input type="text" 
                       name="PostCode" 
                       value={property.PostCode}
                       onChange={onChange}
                       className=""
                       placeholder="Postcode"/>
                <label htmlFor="NoBeds">Beds</label>
                <input type="number" 
                       name="NoBeds" 
                       value={property.NoBeds}
                       onChange={onChange}
                       className=""
                       placeholder="Number of beds"/>
                <label htmlFor="NoBath">Bathrooms</label>
                <input type="number" 
                       name="NoBath" 
                        value={property.NoBath}
                       onChange={onChange}
                       className=""
                       placeholder="Number of bathrooms"/>
                <label htmlFor="NoLivingRooms">Living Rroom</label>
                <input type="number" 
                       name="NoLivingRooms" 
                        value={property.NoLivingRooms}
                       onChange={onChange}
                       className=""
                       placeholder="Number of living rooms"/>
                <button className="" 
                        type="submit">Submit</button>
            </form>
            {message ? <Message message={message}/> : null}
        </div>
    );

}
The error appears to be related to the second line of the code below. I can post using POSTMAN but when it comes to trying in the front end, It's just errors.

postProperty : property => {
        return fetch('/user/property', {
            method : "post",
            body : JSON.stringify(property),
            headers: {
                'Content-Type' : 'application/json'
            }
        }).then(res => res.json())
        .then(data => data);
    }
}