How to move a document from SharePoint 2016 document library

 This will be a server side solution and will involve basic deployments

This is the most favourable approach. SharePoint Designer, Nintex and K2 can handle this scenario. SPD is free, but the others are not

Schedule a PowerShell script to look for any new item creation in the list. Then identify the new item(s), download its document/attachment and then move the file to your desired location. This is a cumbersome process though. See this link for more details -

https://sharepoint.stackexchange.com/questions/150672/how-to-call-powershellscript-ps1-on-sharepoint-list-list-item-created

Idea here is same like Powershell. Capture the event of new item added. Then download the attachment/document, and add the same in your desired location. These links below might help.

 

https://sharepoint.stackexchange.com/questions/148902/how-to-call-javascript-function-when-a-new-item-is-added-to-a-specific-list

 

 https://stackoverflow.com/questions/47444317/adding-attachments-to-sharepoint-list-item-using-client-side-code-unreliable