How to change the owner of a story

For this you will need the Graphql id of the story (see How to get a Story) and the user you want to assign the story to.

graphql
mutation storyChangeOwner($input: StoryChangeOwnerInput!) {
storyChangeOwner(input: $input) {
clientMutationId
story {
id
user {
id
}
}
}
}
variables
{
"input": {
"id": "STORY_ID",
"owner": "OWNER_ID"
}
}

Expected result:

response
{
"data": {
"storyTag": {
"story": {
"id": "STORY_ID",
"user": {
"id": "OWNER_ID"
}
}
}
}
}