Add custom web part to page SharePoint 2013 c# csom

I am trying to write c# code to add custom webpart programmatically to SharePoint 2013 page.

I tried searching net and stackoverflow but couldn't find any proper article or blog which can help me to achieve this.

You could use the the Webpart XML content to add a Webpart in page using CSOM, below is my sample for you. It's adding a document library to the page:

            var wpXML = @"<?xml version='1.0' encoding='utf-8' ?>
<webParts>
  <webPart xmlns='http://schemas.microsoft.com/WebPart/v3'>
    <metaData>
      <type name='Microsoft.SharePoint.WebPartPages.XsltListViewWebPart, Microsoft.SharePoint, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c' />
      <importErrorMessage>Cannot import this Web Part.</importErrorMessage>
    </metaData>
    <data>
      <properties>
        <property name='ListUrl' type='string'>Shared%20Documents</property>
        <property name='MissingAssembly' type='string'>Cannot import this Web Part.</property>
      </properties>
    </data>
  </webPart>
</webParts>";

            var page = ctx.Web.GetFileByServerRelativeUrl("/sites/test/SitePages/wiki1.aspx");

            var wpm = page.GetLimitedWebPartManager(PersonalizationScope.Shared);
            ctx.Load(wpm);
            ctx.ExecuteQuery();

            var importedWebPart = wpm.ImportWebPart(wpXML);
            var webPart = wpm.AddWebPart(importedWebPart.WebPart, "mainContent", 0);
            ctx.ExecuteQuery();