This script redirects you to a post with real ID from the post page with pfbid.... Just run it in browser's console on the pfbid... post's page.

getrealidfrompfbid.js

async function fetchFacebookPostId() {
  const inputUrl = window.location.href;

  if (!inputUrl || !inputUrl.includes("pfbid")) {
    alert("No pfbid found in URL!");
    return;
  }

  const fetchUrl = `https://www.facebook.com/plugins/post.php?href=${encodeURIComponent(inputUrl)}`;

  try {
    const response = await fetch(fetchUrl);
    const html = await response.text();
    const realId = extractRealId(html);

    if (realId) {
      const realUrl = `https://www.facebook.com${realId}`;
      window.location.href = realUrl;
    } else {
      alert("Unable to extract the real post ID!");
    }
  } catch (error) {
    console.error("Error fetching the post.php URL:", error);
  }
}

function extractRealId(htmlString) {
  // Create a new DOM Parser
  var parser = new DOMParser();
  // Parse the HTML string
  var doc = parser.parseFromString(htmlString, 'text/html');

  // Use querySelector to find the element with the specific href
  var link = doc.querySelector('div[role=feed]>a');

  // Check if the link is found
  if (link) {
    // Extract the href attribute
    var href = link.getAttribute('href');
    return href;
  } else {
    // Return a default or error message if not found
    return null;
  }
}

await fetchFacebookPostId();