1. commercials / Advertising / leads.
2. In-app purchases of things that they actually need.
3. Freemium model - they only pay for extra services (like maybe you can have a dating feature or a business feature).
4. Offering complimentary services such as loans, help submitting forms, help before interviews and many other ideas.
There are many more options. Happy to explain them on a call.
I've successfully helped over 380 entrepreneurs, startups and businesses, and I would be happy to help you. After scheduling a call, please send me some background information so that I can prepare in advance - thus giving you maximum value for your money. Take a look at my reviews: https://clarity.fm/assafben-david
Creating a revenue model for social learning app will require you to understand how the online education works. I believe this link will help you a lot: https://www.oerknowledgecloud.org/archive/SSRN-id2778323.pdf
Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath
I think you've got a great answer by Assaf Ben-David.
In addition, it might be worth considering partnerships and who else might benefit.
For example, could your client also/instead be the educational institutions where the students study?
Is there a benefit to them somehow?
It's true that students are cost-sensitive but can you offer them something they can't live without? Worth considering and refining the value proposition and the price point.