In this blog, we have discussed adding, retrieving, and deleting the SharePoint online quick launch navigation menu using the C# Server Object model. Follow the below coding to get the result.
SharePoint-2013-Hosting1

Add new term in the quick launch

Add the below code in your Program.cs.
After running the code,

Get Navigation node

Add the below code to get all the term from quicklunch.

Delete Navigation Node

Add below code to remove the quick launch term
After running the code,
From the above example of the code, we can conclude that, the CRUD operation of a quick launch navigation node in SharePoint Online using c# is very effective as it reduces the amount of time. You can also use this code for SharePoint 2019 and 2016.