If you have a U.S. bank account, it likely offers Zelle:

Zelle is a direct bank-to-bank instant ACH transfer with no fee at all: thousands of U.S. banks offer it! Scan or click the above QR code to find your bank. If your bank offers Zelle, use your online banking to donate. If you need a tax-deductible receipt, contact us when you've donated. (For recurring donations, contact your bank to set it up.)
Otherwise, go to our Donate page for PayPal (about 3% fee) or sending us a check.