Gmail only allow emails from contacts: three ways that work.

Option 2: a free Apps Script that reads Google Contacts

This Google Apps Script labels and archives inbox mail from anyone who is not in your Google Contacts or Other contacts. Set ARCHIVE to false to label only.

// Screen Gmail senders who are not in your Google Contacts.
// Runs in your own Google account. Nothing is sent to KeepKnown.
const LABEL_NAME = 'Not in contacts';
const ARCHIVE = true; // true: label and archive. false: label only.
const SEARCH = 'in:inbox newer_than:1d';

function screenInbox() {
  const known = knownAddresses_();
  const label = GmailApp.getUserLabelByName(LABEL_NAME) || GmailApp.createLabel(LABEL_NAME);
  GmailApp.search(SEARCH, 0, 100).forEach(function (thread) {
    const labelled = thread.getLabels().some(function (existing) {
      return existing.getName() === LABEL_NAME;
    });
    const fromKnownSender = thread.getMessages().some(function (message) {
      return known.has(addressOf_(message.getFrom()));
    });
    if (labelled || fromKnownSender) return;
    thread.addLabel(label);
    if (ARCHIVE) thread.moveToArchive();
  });
}

function knownAddresses_() {
  const known = new Set([Session.getActiveUser().getEmail().toLowerCase()]);
  GmailApp.getAliases().forEach(function (alias) {
    known.add(alias.toLowerCase());
  });
  let pageToken;
  do {
    const page = People.People.Connections.list('people/me', {
      personFields: 'emailAddresses',
      pageSize: 1000,
      pageToken: pageToken,
    });
    (page.connections || []).forEach(function (person) {
      addEmails_(known, person);
    });
    pageToken = page.nextPageToken;
  } while (pageToken);
  do {
    const page = People.OtherContacts.list({
      readMask: 'emailAddresses',
      pageSize: 1000,
      pageToken: pageToken,
    });
    (page.otherContacts || []).forEach(function (person) {
      addEmails_(known, person);
    });
    pageToken = page.nextPageToken;
  } while (pageToken);
  return known;
}

function addEmails_(known, person) {
  (person.emailAddresses || []).forEach(function (email) {
    known.add(String(email.value).toLowerCase());
  });
}

function addressOf_(from) {
  const match = from.match(/<([^>]+)>/);
  return (match ? match[1] : from).trim().toLowerCase();
}

The script checks your Google Contacts and Other contacts (people you have emailed) on a timer, so new mail can sit in the inbox for a few minutes. Apps Script has daily quotas and a 6-minute limit per run, and you maintain the code yourself. To let a sender through, add them to Google Contacts; mail you move back keeps its label and is not archived again.