For Technical Feature Available ..

first go to setting --> users -->users --> Administrator --> Access rights --> at last there is a fields of TEchnical Feature --> check it

now go to  settings / technical / sequences and identifiers / sequence /sale entry / sale journal / and then set the increment no = 1

thnk you

Check the sequence settings in settings / technical / sequences and identifiers / sequence. Make sure the increment number is 1 in the sales journal entry. 

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