See "A researcher has wrongly claimed co-authorship of my publication" in https://help.researchgate.net/hc/en-us/articles/14292798510993 for instructions how to correct this. But unlike this help page suggests, most probably it was not the other author himself who wrongly claimed co-authorship, but ResearchGate's automatic algorithm wrongly identified another researcher as co-author and assigned your publication to his profile. This is a frequent problem in ResearchGate in case of similar names.
Thanks for the help. I am going to correct the mistake, made by the ResearchGate's algorithm, using the received link. A women with similar name was put into the list of the authors instead of my dead male colleauge, who may not be in the author's list of the ReaserchGate.