It's not only for work....Actually, the time you can use it for work is limited.
You can only use it for work if you have a valid EAD.
Give them your SSN, you can use it for almost anything.
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Self filed AOS │Apps Received By USCIS - 3/18/19
│Biometrics Done - 4/11/19
Interview Scheduled - 4/24/19│Interview Date - 5/31/19│AOS Approval - 5/31/19
Permanent Resident Card Received - 6/8/19