Who levied taxes on new converts to Islam?

Who levied taxes on new converts to Islam?

نئے اسلام قبول کرنے والوں پر ٹیکس کس نے لگایا؟
Explanation

Jizya tax was imposed on Non-Muslims during the Holy Prophet's (PBUH) life

But it was formalized during Caliph Umar bin Khatab.