See this help page for instructions how to add published or unpublished research to your ResearchGate profile: https://help.researchgate.net/hc/en-us/articles/14293005132305-How-to-add-research
Thank you for your help. I have added one of my publications, but only privately, as I am unsure of its copyright status. Can the abstract and reference still be included?
Adding the abstract is always possible, I think. - What do you mean by "reference" in connection with adding publications? - Concerning the full text, most publishers/journals allow posting preprint versions. For my own publications, I produced such "preprints" after publication, like, e.g., in https://www.researchgate.net/publication/351454584. - See more about copyright in https://help.researchgate.net/hc/en-us/articles/14846037644817-Copyright-and-ResearchGate.