How do I get paid to take elderly neighbor to medical appointments?

Unless you request payment of your neighbor there is no way to get paid for this.

When dh can’t take me to appointments for what’s turned out to be an eventual hip replacement, his friend drives up and takes me. I pay him 40 per trip.

Neighbor pays you for the gas at least. Office if Aging should have a bus service for Seniors for appts and running errands.

The person you are driving for would need to pay you.