If you currently live in the United States and want to work for a U.S. employer while your green card application (Form I-485) is pending, you will need a work permit first. Generally, everyone applies for I-765 with I-485 to get the EAD card which will allow them to work during the pending I-485. So, you will be allowed to work after getting the EAD card while your I-485 is pending. You may not apply for a work permit if you live abroad.
Your category is C9. Pending adjustment of status under Section 245 of the Act – category is C9.
I-485 EAD processing time is 2 to 6 months at the National benefits center. If you have an emergency situation, you can expedite the process by communicating with USCIS.