These third party payment processors report the amount of payments processed each year for your organization to the IRS. This is done on a form 1099-K. In previous years, there was a minimum threshold for number of transactions or gross amount of total payments reported.
Starting in 2022, the minimum transaction threshold will be removed and transactions totaling $600 will be reported on form 1099-K. There is no special accommodation for 501(c)7 organizations in this new regulation.
501(c)7 tax-exempt organizations like fraternities and sororities should continue to report all revenue, including that from payments processed by Venmo and other third party payment processors, on their 990 tax return.
If you receive a form 1099-K from Venmo, Paypal, etc for payments not processed through Vault, you must provide that to your tax preparer.
See IRS website for more information on 1099-K reporting:
https://www.irs.gov/payments/general-faqs-on-new-payment-card-reporting-requirements