thank youRPRF is a mandatory fee which can be paid at a later time than your application fee, but it does not mean your application has been approved. They can refund you this amount when they reject your application (Reference: https://ircc.canada.ca/english/helpcentre/answer.asp?qnum=1396)
Can you provide any link to these "online" sources saying "because you got a request to pay RPRF, your PR is approved"?. I seriously doubt that is the case.
This request for RPRF is same as request for Biometric fees. Until you receive your COPR, your application has not been approved. (https://www.canada.ca/en/immigration-refugees-citizenship/services/immigrate-canada/express-entry/application-approved.html)
See https://www.canadavisa.com/canada-immigration-discussion-board/threads/the-anatomy-of-a-background-check-in-depth-analysis.500146/ for a better understanding
it's nothing official on ircc sites just asked around in Reddit and discord groups
what should i be waiting for after i send the rprf and updated proof of funds if you have any idea of what usually comes next?