I think you refer to this profile https://www.researchgate.net/profile/Ida-Flink-2 If I recall correctly (and read in the link given by Wolfgang R. Dick ) all you have to do is to log into your latest profile/account and after that the only thing you have to provide for the profile you want to merge is the (old) e-mail address (so no password). I guess it is the one you used in the paper where you were the corresponding author:
By the way when I search for your name Ida Flink in research here on RG I end up with a list of papers https://www.researchgate.net/scientific-contributions/Ida-Flink-2217479154 which are not claimed yet. It would be a good thing to claim authorship (so they will end-up in your current profile), see https://help.researchgate.net/hc/en-us/articles/14292798510993-Authorship how you can do this.
Best regards.
PS. If this all somehow doesn’t work you can read in the link provided by Wolfgang R. Dick that there is some info about “I can’t remember the login email address of my duplicate account. What can I do?”
By the way an example of a paper that is not claimed by you (and thus is not present in either of your profiles) is:
Article Expecting the worst: pain catastrophizing and intolerance of...