A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
Dear MingSin Kwok,
Good day!! Wish you a happy new year~
I understand your concern and to my knowledge, I am sorry to convey that the order you are looking to achieve in the SharePoint Online document library is not possible because the folders in the document library will be in the order and then the files.
I agree with you on having the ability to arrange the files and folders in the custom order on the document library of the SharePoint Online will benefit the users and I suggest you add your valuable ideas as feedback in the SharePoint · Community which is the best place to share our ideas and improve the Microsoft products.
Appreciate your patience and understanding. Have a great day!!
Best Regards,
Sophia