Need to open prior period in GL which are before the first open period in Specify ledger option

Summary:

While given GL setup for secondary books in 'specify ledger' options, we have given the first open period as Jan-22.

But now i understand we need to enter some transaction in the prior period of Dec-21.

In the system it does not show periods before Jan-22 as this is the first open period.

Please let know how can we enter transactions in the period of DEc-21.

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