Assuming they have a Social Security card authorizing them to work. Apparently, this can be issued at the same time as the green card, at least in recent years, but some people did not include the request with their visa application and were advised to go to a Social Security office. They might not have thought it was important, or they might have already had an SSN, without employment allowed, before the green card was issued.
You might want to bookmark these links and read the IRS guidance:
One for each EIP.
"Level Up" is a gaming function, not a real life function.