GST Rate on export invoice (IT based service) - 18% or 0%?

Hello everyone!!

I'm a freelancer offering web development services to both Indian and foreign clients. For Indian clients, I invoice at 18% GST rate but wondering at what rate I must invoice the foreign clients.

Since exports of services is 'zero rated' under GST regime, should I invoice foreign clients at 0%? Or, should I invoice at 18% and then simply do not pay the tax? (LUT has been furnished for export of services.)

Kindly assist. Thank you!