Getting order number in shopify new payment app

[maunaw]

Hi, I have my public payments app working fine but unfortunately I am not able to get #1002 numeric order number by any means in this app, although customers receives it in their email confirmation. 

IS there any way we can get this order number through any api or graphsql request from shopify?

I would like to get order number based on paymentsession id which shopify sends or if there is any other way that we can fetch this order number?

Please help or suggest on the same at the earliest.

Thanks, Mana