I94 is the form that provides your arrival and departure record to USA. Whenever you enter US, you’ll get a new I94 number at the airport when you clear immigration. The immigration officer will check your passport and visa and assign you a number called I94. You can also get your I94 details online later as well.

After 1 week of arrival, login to the below website, click on “Get Recent I94”, fill up the details and the site will show the latest I94. You just need to take a print of the document and keep it with you (and take it as proof to SSA Office)

https://i94.cbp.dhs.gov/I94/#/home