Hi @Ki Bang ,
As per my understanding, you set Item-level Permissions to "Read items that were created by the user" and "Create items and edit items that created by the user" in advanced settings. Also, you give the users "Read" permission level to the list. You are wondering why users cannot create new item in the list. Is my understanding correct?
Your operation in advanced settings is right, users will only be able to read and edit items created by themselves. However, if you only give Read access to those users, it is not enough to make them be able to create items in the list. You must at least give them Contribute
permission level if you wanna them have access to create items in the list.
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