Magento 2.x using Multiple Shipping Address to ship products in customer’s multiple address.
The Following below admin setting required to enable Multiple Shipping Address.
Step [1] – Go STORES > Configuration, redirects Configuration section.
Step [2] – Left panel, choose SALES > Shipping Settings.
Step [3] – Right panel, Expand the Origin section
There are following below two part
[a] – Allow Shipping to Multiple Addresses
To Enable select Yes, after uncheck use system value
[b] – Maximum Qty Allowed for Shipping to Multiple Addresses
Enter required quantity as per Store need.
Step [4] – Click on Save Config button & run CLI command Flush
Finally, Multiple Shipping setting has been done.