Billing with OTP:
From Admin login you need to specify one Contact no on which OPT code will be shared to Generate Billing for Ad-hoc and Structured format.
Navigate: Top Right Circle -Sytem Config
Account Settings - Billing Setting- Enter PHONE no in Mobile no section to get the Billing OTP.
After completing first step from Admin Side then log in as Partner/Manager/Article/Accountant/HR/Employee
In Billing it will activate the option as highlighted for both the billing.
New Bill Ad-hoc/Structured Billing:
In the billing there is field called OTP .After clicking on Generate OTP a text message will be received in the number, you need to enter the 4 digit code and click on submit button.