Sometimes, a "No Password" 7z file contains another 7z file inside it that does require a password.
If the title says "No Password" but the software asks for one, the uploader may have made a mistake, or the file is a "locked" version of the set. AMS Cherish SET 130 No Password 7z
If possible, open the file in a virtual machine or a "sandbox" environment to prevent any potential malware from reaching your main OS. Sometimes, a "No Password" 7z file contains another