from gcore import Gcore

client = Gcore(
    api_key="My API Key",
)
task_id_list = client.cloud.instances.resize(
    instance_id="instance_id",
    project_id=0,
    region_id=0,
    flavor_id="g1s-shared-1-0.5",
)
print(task_id_list.tasks)

{
  "tasks": [
    "d478ae29-dedc-4869-82f0-96104425f565"
  ]
}