I'm in the same boat as you (education website and need to accept international payments)
I assume that paypal is not an option for you (for me, it is, but I want to stop using paypal), so I did a bit of research and found all these payment gateways that could be good options:
2checkout
stripe
authorize.net
payeer
paymentwall
Payeer seem pretty scumbag-y, I contacted them to help me implement their processor on my pages and they couldn't be bothered, they just threw a PDF in my face with the attitude of "here, follow these instructions and stop bothering me", then I told them that those instructions are too complicated for me (they do seem complicated, too much coding for my taste) and I asked them for assistance and they told me that everything's covered in the PDF. I told them that I know that everything's covered in the PDF but the info in that PDF is too technical for a newbie so I asked them again to implement a payment button on one of my pages and then I'll do the rest of it and they told me to watch tutorials on youtube lol
At that point I've had it with them, so I looked for a different option, and I found paymentwall. I contacted PW support to test the waters and they've been very responsive and helpful... well, I still had to repeat a question 2 times cause they didn't understand from the first time, but at least they've carefully re-read it and answered exactly what I needed to know.
So, for me, PW might be a good option but they told me that the only way to accept international payments for digital products (ebooks) at the moment (that was 1-2 months ago) is to install WooCommerce plugin set it up to accept PW payments. I've not done that yet cause I never liked WooCommerce, the first (and last) time I've installed it on a website some 7-8 years ago it had 100s or 1000s of settings and I freaked out and uninstalled it
But probably that I'll re-install it again, maybe they have gotten ridden of all those idiot settings in the meantime. So yeah, PW seems like the best option for us at the moment. And authorize.net seems a good option, too, but I don't know if they allow me to sell ebooks using their payment processor, and they cost $25 per month, too which at the moment I'm not willing to pay.
So anyway, these are pretty much all of the options that I've found. If anyone knows of other (better options) that doesn't involve paypyal, please share!