I have the below requirement in SharePoint Online and On-prem versions:
A custom list is to be maintained where users can edit only items that were created by him/her. Enabling unique permission for each item is not an option as the list is expected to have large number of item. Also, the user should be able to add new items. If a user tries to edit items created by other user, he/she should get an error message informing that this action is not allowed.
Could you please suggest if this is possible by using any dev options in SharePoint and/or Power Platform?