https://goodchange.app/donate/votetombartole
GoodChange offers one time, recurring (monthly), and spare change round-up options.
(Spare Change round-up is an option which will round up credit/debit card purchases to the nearest dollar, and donate that change at the end of the month. The average monthly donation, with normal use, is around $20. This option is pausable if use is high or expected to be high.)
https://secure.actblue.com/donate/votetombartole
ActBlue offers secure one-time and recurring options for Contributions.