is it just me or you cannot put a legendary creature in comm

is it just me or you cannot put a legendary creature in command zone ?
i could put only planeswalker, sorcery, instant
just no creature...
did i do anything wrong or the option doesn't exist ?
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ops: edit seems you first need 1 copy of card in the deck, then you switch to coomand zone, then you move the creature
edit2: so if you select a format in the deck builder, then click card catalog you set up the format used
i could put only planeswalker, sorcery, instant
just no creature...
did i do anything wrong or the option doesn't exist ?
------------
ops: edit seems you first need 1 copy of card in the deck, then you switch to coomand zone, then you move the creature

edit2: so if you select a format in the deck builder, then click card catalog you set up the format used