Setting Up Banner Image in Programmatic Way

Hi All,

I was trying to add background image in header section of sharepoint site.

Through sharepoint UI we were following below step to set the background image of header section:

 Settings -> Change the Look -> Header -> Set the header layout as "Extended" ->

Set the required background image as Optional Image. 

Now we are looking for a programmatic way, either from powershell or PnP-Provisioning Template to apply the same background image to number of sites. 

Any Suggestions are appreciated.

Thank You.