As per Section 2(6) of IGST Act, 2017-
(6) “export of services” means the supply of any service when,––
(i) the supplier of service is located in India;
(ii) the recipient of service is located outside India;
(iii) the place of supply of service is outside India;
(iv) the payment for such service has been received by the supplier of service in convertible foreign exchange; and
(v) the supplier of service and the recipient of service are not merely establishments of a distinct person in accordance with Explanation 1 in section 8;
If you satisfy the above criteria, it amounts to export of service and you need not pay any GST, since exports are zero rated as per Section 16 of IGST Act. However, as per Section 22/23 of CGST Act, 2017 you need to take GST Registration, in case you wish to claim any refund of ITC on input services procured by you in exporting your service. You will also have to execute a bond in this regard with your jurisdictional Dy/Asst. Commissioner.