Please go on Facebook marketplace and search for diapers. Some people give them out for free and some for few bucks. I just checked your town and they have few listed.
If you have PayPal I can send you something as I’m in the uk
Do you live in UK? At my local family hub (previously known as children’s centres or sure start centres) lots of people donate various size nappies if you could ask a place like that? Do you also have a local facebook group for your area in which people give away things and swap things for free? Maybe you could have a look see if such group exists for your local area and post something in there - I’m sure lots of local mums will have spares.