Need gstin coding field name

hi
i am trying to make my own template
but unable to get coding field name for tax.
will anyone help me for the same.

another thing some times because of more items my invoice become 2 pages
how can i ass page number in invoice

Templates are no longer part of Manager, that feature is now called Themes.
If you can still see Templates as an option, then you need to update

please check
https://www.manager.io/guides/10388
for detailed guide