问题在于你在调用后如何设置数据，在你的代码中，你在try and catch内部声明数据，并在try and catch外部使用它。基本上意味着你将数据重新分配给它本身：
1.在数据尝试和捕获之外解密数据
1.使用响应而不是数据：
const response = await fetch（'/API/about'，{ method：'POST'，body：formData，}）;
1.然后将response赋值给data setData（respone）
完整的代码看起来类似于这样：

import { Button, Input, Textarea } from "@nextui-org/react";
import React, { FormEvent, useState } from "react";
import { useRouter } from "next/router"; 

const adminAbout = () => {
  const router = useRouter();
  const [data, setData] = useState(null); 

  async function handleSubmit(e: FormEvent<HTMLFormElement>) {
    e.preventDefault();
    try {
      const formData = new FormData(e.currentTarget);
      const response = await fetch('/api/about', {
        method: 'POST',
        body: formData,
      });
      if (response.ok) {
        const responseData = await response.json();
        setData(responseData);
        router.refresh();
      } else {
        console.error("Request failed with status:", response.status);
      }
    } catch (error) {
      console.error("An error occurred during the process:", error);
    }
  }
  return (
    <section className="mx-auto py-10 p-5 flex flex-col max-w-lg">
      <div className="">
        <h1 className="py-5 font-bold">About Form</h1>
        <form onSubmit={handleSubmit}>
          <Input name="name" placeholder="Name" />
          <Textarea name="description" placeholder="Description" />
          <Button type="submit">Submit</Button>
        </form>
      </div>
    </section>
  );
};
export default adminAbout;

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