Creating Company & Opportunity Returning 500 On REST API

await fetch(
    "https://my-url.com/rest/companies",
    {
      method: "POST",
      headers: {
        "Content-Type": "application/json",
        Accept: "application/json",
        Authorization: `Bearer ${process.env.CRM_API_KEY}`,
      },
      body: JSON.stringify({
        name: body.businessName,
        opportunities: [
          {
            name: "Test Opportunity",
          },
        ],
      }),
    },
  );