Use CLI to add a card to a set causes error

[dbriscoe511]

I'm attempting to add a card to a set using the CLI. I'm wondering if there is just not a way to do this right now? Please let me know if I am just doing something wrong here. I read through the docs here and I could not find a way to do this. Sorry if this is a newbie question

:load .\my.mse-set
my_card := new_card([name: "Prismagoyf", text: "Prismagoyf’s power is equal to the number of colors among cards in all graveyards and its toughness is equal to that number plus 1", type: "Lhurgoyf", super_type: "Creature", casting_cost: "2", pt: "*/1+*", card_color: "blue", rarity: "uncommon", illustrator: "GPT 4o", set_code: "FRW"])
cards := set.card
cards := cards + [my_card]
set.card := cards
write_set_file(file:"my.mse-set")

output

> > <card>
> [<card>,<card>]
> [<card>,<card>,<card>]
> ERROR: (11): Can only assign to variables
ERROR: (12): Expected 'end of input' instead of 'cards'
> "my.mse-set"