GST appeal procedure governs filing limits, pre-deposit, acknowledgements, hearing, and disposal before the Appellate Authority. Appeal to the Appellate Authority under the GST law is available to an aggrieved person within three months, with electronic filing in FORM GST APL-01 or limited manual filing where permitted. Filing is subject to prescribed acknowledgements, signature requirements, and submission of a self-certified copy where the order is not uploaded on the common portal. The Commissioner may also direct a subordinate officer to file an application in FORM GST APL-03 within six months, and delay may be condoned up to one month.