The Prophet ﷺ said, "There is no valid marriage without a guardian."
حدثنا عبد الواحد الحداد قال ثنا يونس عن أبي بردة
أن النبي ﷺ قال لا نكاح إلا بولي
No references are available.
Its isnad is sahih. Abdul-Wahid the Haddad is Ibn Wasil Sadusi, Abu Ubayda, and he is trustworthy, his hadith is found in Bukhari. The hadith was mentioned previously at 19598.