虽然您无法隐藏从浏览器发出的请求，但可以使用API路由来屏蔽外部服务的URL。
创建一个调用https://formsubmit.co/ajax/your@email.com的API路由（假设为/api/form-submit），并将充当代理。

// /pages/api/form-submit
export default async function handler(req, res) {
    if (req.method !== "POST") {
        res.setHeader('Allow', ["POST"])
        return res.status(405).end(`Method ${req.method} Not Allowed`)
    }

    try {
        const res = await fetch("https://formsubmit.co/ajax/your@email.com", {
            method: "POST",
            headers: req.headers, // Headers passed from the client-side
            body: req.body // Body passed from the client-side
        })
        const data = await res.json()
        res.status(200).json(data)
    } catch(e) {
        res.status(500).end(`An error occurred: ${e}`)
    }
}

然后从客户端，对新创建的API路由发出请求。

const handleSubmit = async (e) => {
    e.preventDefault();
    await fetch("/api/form-submit", {
            method: "POST",
            headers: {
                "Content-Type": "application/json",
                Accept: "application/json"
            },
            body: JSON.stringify({
                name: "FormSubmit",
                message: "I'm from Devro LABS"
            })
        })
        .then((response) => response.json())
        .then((data) => console.log(data))
        .catch((error) => console.log(error));
};