Venmo supports uploading debit and prepaid cards from several major brands, including American Express, Discover, MasterCard, and Visa. If you have a card from one of these companies, you'll be able to add it to your Venmo account.
However, Greenlight does not link directly with Venmo. You cannot use your Greenlight card on Venmo as it is a prepaid debit card.
There is a way to facilitate the transaction of Venmo to Greenlight credit. It's the same process described above for adding money from Cash App to Greenlight debit card.