Treatment of GST on supplies to SEZ

My client started supplying goods to customer in SEZ.  How to charge GST and as GST not chargeable, how to get credit of Input tax? Is there any other method in which bond etc is not required?  

At present, we are charging GST but party is not paying it.  Hence we pass journal entry of reversal of GST .  But I am satisfied with this.  What entries I need to pass and get credit of ITC?