Upload multiple files on SharePoint 2019 in one item inside a document library / list item

Question

I want to upload multiple files in SharePoint list \ library. I don't want to keep files and metadata in separate list.

I am currently using C# code for uploading the files to SharePoint list. But in document library only one document is allowed per item. I have tried uploading multiple items in one item under document library but it either creates a new item or replace the existing one but does not allow multiple files in one item.

I am using SharePoint 2019 on-premise.