Turn off 'Double Opt-In'

Turn off 'Double Opt-In'

Hello,
I am using Zoho 'Sign in Forms' to enable users to subscribe/register.
I want to turn off the 'ouble opt in' functionality i.e. Users should be able to subscribe without having to confirm their email.

Please let me know if there is a fix/code change that I can do to achieve this.

Thanks
George