The non-resident taxable person shall furnish a return in FORM GSTR-5 electronically through the Common Portal, either directly or through a Facilitation Centre notified by the Commissioner, including therein the details of outward supplies and inward supplies and shall pay the tax, interest, penalty, fees or any other amount payable under the Act or these rules within twenty days after the end of a calendar month or within seven days after the last day of the validity period of registration, whichever is earlier.

Source: CBIC Website