If you want to send an e-invoice to a customer in Malaysia you will need to verify your identity with the Malaysian government for safety reasons. This process is known as 'Know Your Customer' or KYC.
A valid proof of identity for this process is a excerpt from the business registry or a document where you assign Billit as your Access Point or Service Provider:
Are you looking for all the steps to send an invoice to Malaysia? Read the entire process on e-invoicing in Malaysia.