See this help page ("How to add research") for instructions how to create a page for a publication: https://help.researchgate.net/hc/en-us/articles/14293005132305. In case of a paper which is not open access, do not upload a file with the paper, just add the bibliographic data. You may add a link to the abstract field to the paper's page at the journal's website. Or if the paper has a DOI such a link will be created automatically.
In my opinion the best way to post an not open access paper is to upload the accepted manuscript including the DOI of the published version. See, for example, the Public Full-text in this publication:
Article Basal Heave Stability Analysis of a Circular Shaft Excavatio...
Dear Cemil Keski̇noğlu To my knowledge, the accepted versions, without editing processing, can be published in RG. Do you know of any journals that explicitly say you can't do this?
Dear Cemil Keski̇noğlu according to the capture you send, there is no restriction when publishing the accepted version (without editing processes) in RG. I have always published the accepted version in RG, without any problem.