I already did it. means created a new site and installed my custom app into new site but still that changes does not reflecting on my new site.
more elaborate this thing for all.
1 ) First, I created a new site and install an ErpNext app into a new site.
and enabled developer mode using "bench set-config developer_mode 1 " command.
Then I go to delivery note inside the Stock menu then click on Menu Button that available on the top right side in Delivery Note.
Click on customize button and add one button named calculate delivery charge and one float field delivery Charge and update doctype.
then I export customization into my custom app Using “Export Customization” Button.
In my app created a Custom directory that contains my custom field and button in delivery_note.JSON file.
Then Reload screen so, my two custom field and button both display but when I am creating a new site and install my custom app both field and button is not displayed on a new site.
I solved issue to load or reflect customization into a new and existing(current) site.
i just restart the system and take latest pull of the frappe and erpnext and removed cache using below command.
" bench clear-cache
bench update
bench migrate
bench build
bench clear-cache
bench start "