Dear respected RS12348971,
Good day! Thank you for posting to Microsoft Community. We are happy to help you.
I’m sorry you’re having a problem but based on your description we can work together to resolve it.
For the situation you encountered, we deeply understand the inconvenience caused and apologize for it.
As per your description, to duplication file/Folder in SharePoint online document library we generally use "Copy To" option. Since you mentioned, "I cant see it on Sharepoint" If possible, could you please upload screenshot for our reference, so we can understand your exact scenario and provide our suggestion in a productive manner, perhaps some related screenshots will be helpful.
Meanwhile, may I know are you using SharePoint online document library in Classic view? Please make sure to working in a modern experience of SharePoint online document library
Also, please make sure you did not look on a "Document Library" web part in SharePoint page. Switching over to the actual Document Library brought to get Move/Copy buttons.
Please understand that our initial reply may not always immediately resolve the issue. However, with your help and more detailed information, we can work together to find a solution.
Appreciate your patience and understanding and thank you for your time and cooperation.
Sincerely,
Waqas Muhammad