Evidence of birth is essential for most adjustment of status and immigrant visa applications, the two processing paths for a green card.
Although there are exceptions for asylees and refugees, applicants generally must submit a foreign birth certificate (if available) with Form I-485, Application to Register Permanent Residence or Adjust Status or the DS-260.
However, some governments or local civil authorities in certain countries didn’t issue official birth certificates at the time of your birth.
In these cases, it’s still vital to submit alternative evidence of birth with your green card application.