Who is Abu Mohamed al-Joulani according to James Jeffrey, former U.S. Ambassador to Iraq?

In 2021, PBS reported that U.S. government was discussing what to do with Abu Mohamed al-Joulani. James Jeffrey, former U.S. Ambassador to Iraq, admitted on camera that Joulani and Hay'at Tahrir al-Sham (HTS) had been in contact with the Americans since the Trump administration