1.
Relevant condition (from Notification No. 11/2017-Central Tax (Rate) as amended till date) reads as follows:
"(2) The option by GTA to itself pay GST on the services supplied by it during a Financial Year shall be exercised by making a declaration in Annexure V on or before the 15th March of the preceding Financial Year: ...."
Heading of Annexure V reads as follows: Form for exercising the option by a Goods Transport Agency (GTA) for payment of GST on the GTA services supplied by him under forward charge before the commencement of any financial year to be submitted before the jurisdictional GST Authority.
And condition (i.e. making a declaration in Annexure V) stands fulfilled by you on 22.02.2023 for FY 23-24 in my view.
W.r.t. filing such declaration 'online' & not 'offline', first, no such thing is prescribed in above referred notification. Even otherwise, filing such declaration offline (instead of 'online') is at best a procedural lapse. And same should not lead to valid denial of option so chosen by you in my humble view.
These are ex facie views of mine and the same should not be construed as professional advice / suggestion.