How do I edit a dropdown value via API

I am wanting to edit the value of a dropdown field that was created. However, whenever I try to edit the value via the API, it always selects the same value.

I wrote a python function function to send the API request (below). I do not receive errors and it seems to work for populating the other value which is a text box. However, when trying to update the value of the dropdown item, it always just sets it to the first option "sugar_value_1".

def update_kanban_link(sugar_token, account_id, task_id, onboardingStage):

match onboardingStage:
case "1":
sugar_stage="sugar_value_1"
case "2":
sugar_stage= "sugar_value_2"
case "3":
sugar_stage="sugar_value_3"
case "4":
sugar_stage= "sugar_value_4"
case "5":
sugar_stage= "sugar_value_5"
case "6":
sugar_stage="sugar_value_6"
case "7":
sugar_stage="sugar_value_7"
case "8":
sugar_stage="sugar_value_8"
case "9":
sugar_stage="sugar_value_9"
case "10":
sugar_stage="sugar_value_10"
case "11":
sugar_stage="sugar_value_11"
case "12":
sugar_stage="sugar_value_12"
case "13":
sugar_stage="sugar_value_13"

print(sugar_stage)
kanbanUrl=f'{Kanbanurl}'
url= "{sugar_instance}"
headers= {"Authorization" : "Bearer " + sugar_token}

data= {
"kanban_link_bc_onboard_c":f"{kanbanUrl}",
"bc_onboarding_stage_c": :sugar_stage

}

result=requests.put(url=url+account_id, headers=headers, data=json.dumps(data))

return result