See if you have online generated EWS certificate then you can take a color print of the document and sign it by yourself. Then you can scan it and upload it on the portal where you need to upload it.

The eligibility for the EWS certificate are:

• The annual income of the family of candidate should not exceed 8lakh per annum.
• The family should not hold 5 or more than 5 acres of land.
• The family shouldn't have a residental area more than 1000 sq feet.

I hope this answer helps. All the very best for your future endeavors!