I have just tried to get ElasticSearch setup using;

bin/otobo.Console.pl Maint::Elasticsearch::Migration

But I get the following error over and over.

[Thu Feb 25 10:38:13 2021] otobo.Console.pl: Use of uninitialized value in subroutine entry at /opt/otobo/Kernel/cpan-lib/URI/Escape.pm line 184.
ERROR: OTOBO-otobo.Console.pl-Maint::Elasticsearch::Migration-10 Perl: 5.26.3 OS: linux Time: Wed Feb 24 21:38:13 2021
Message: DebugLog error:  Summary: Error while performing REST ‚GET‘ request to Controller ‚/tmpattachments/_doc/‘ on Host ‚http://localhost:9200‘. Response code ‚405‘.  Data   : Response content: ‚{„error“:“Incorrect HTTP method for uri [/tmpattachments/_doc/] and method [GET], allowed: [POST]“,“status“:405}‘.

Traceback (2309):
Module: Kernel::GenericInterface::Debugger::DebugLog Line: 232
Module: Kernel::GenericInterface::Debugger::Error Line: 326
Module: Kernel::GenericInterface::Transport::HTTP::REST::RequesterPerformRequest Line: 801
Module: Kernel::GenericInterface::Transport::RequesterPerformRequest Line: 201
Module: Kernel::GenericInterface::Requester::Run Line: 319
Module: Kernel::GenericInterface::Invoker::Elasticsearch::TicketManagement::PrepareRequest Line: 496
Module: Kernel::GenericInterface::Invoker::PrepareRequest Line: 160
Module: Kernel::GenericInterface::Requester::Run Line: 208
Module: Kernel::System::Elasticsearch::ArticleCreate Line: 724
Module: Kernel::System::Console::Command::Maint::Elasticsearch::Migration::MigrateTickets Line: 489

Module: Kernel::System::Console::Command::Maint::Elasticsearch::Migration::Run Line: 135
Module: (eval) Line: 468
Module: Kernel::System::Console::BaseCommand::Execute Line: 462
Module: Kernel::System::Console::InterfaceConsole::Run Line: 88
Module: /opt/otobo/bin/otobo.Console.pl Line: 35