Check HTTP Strict Transport Security header
add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" always;
header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload"
// next.config.js module.exports = { async headers() { return [ { source: '/:path*', headers: [ { key: 'Strict-Transport-Security', value: 'max-age=63072000; includeSubDomains; preload', }, ], }, ] }, }