Attach Multiple Files To SharePoint List Item With Default Attachment Of New Form

In this article, I’m going to explain how to use out of the box to attach multiple files with one click in the default new form of SharePoint’s custom list. So, the help of this we can choose multiple files and attach at a time instead of choosing files one by one to upload.

source https://www.c-sharpcorner.com/article/attach-multiple-files-to-sharepoint-list-item-with-default-attachment-of-new-for/