How to allow 3rd party apps to send POST requests to your API

import { NextApiRequest, NextApiResponse } from "next";
import { prisma } from "~/server/db";

export default async function handler(
  req: NextApiRequest,
  res: NextApiResponse
) {
  const leagueUrl: string = req.query.leagueUrl as string;
  const leagueId: string = req.query.leagueId as string;
  const platform: string = req.query.platform as string;
  console.log("League url", leagueUrl);
  console.log("League id", leagueId);
  console.log("League platform", platform);
  console.log("Req body: ", req.body);

  const league = await prisma.league.findUnique({
    where: { leagueSlug: leagueUrl },
  });

  // Make sure the league is registered in our database
  if (!league) {
    return res.status(404).json({ message: "League not found" });
  }

  // Case where the league hasn't had any data imported yet
  if (league.leagueId === null) {
    await prisma.league.update({
      where: { leagueSlug: leagueUrl },
      data: { leagueId: leagueId, platform: platform },
    });
  } else if (league.leagueId !== leagueId) {
    // Case where the league has already been imported but the leagueId doesn't match
    return res.status(400).json({ message: "Invalid export" });
  }

  res.status(200).json({ message: "Hello from Next.js!" });
}

import { NextApiRequest, NextApiResponse } from "next";
import { prisma } from "~/server/db";

export default async function handler(
  req: NextApiRequest,
  res: NextApiResponse
) {
  const leagueUrl: string = req.query.leagueUrl as string;
  const leagueId: string = req.query.leagueId as string;
  const platform: string = req.query.platform as string;
  console.log("League url", leagueUrl);
  console.log("League id", leagueId);
  console.log("League platform", platform);
  console.log("Req body: ", req.body);

  const league = await prisma.league.findUnique({
    where: { leagueSlug: leagueUrl },
  });

  // Make sure the league is registered in our database
  if (!league) {
    return res.status(404).json({ message: "League not found" });
  }

  // Case where the league hasn't had any data imported yet
  if (league.leagueId === null) {
    await prisma.league.update({
      where: { leagueSlug: leagueUrl },
      data: { leagueId: leagueId, platform: platform },
    });
  } else if (league.leagueId !== leagueId) {
    // Case where the league has already been imported but the leagueId doesn't match
    return res.status(400).json({ message: "Invalid export" });
  }

  res.status(200).json({ message: "Hello from Next.js!" });
}