I made a request like this based on the here answer, but the checkbox is not displayed correctly in Confluence.
curl --request PUT \
--url "https://$domain/wiki/api/v2/pages/$pageid" \
--user "$user:$token" \
--header 'Accept: application/json' \
--header 'Content-Type: application/json' \
--data '{
"id": "<page id>",
"status": "current",
"title": "Create Page from Confluence API",
"body": {
"representation": "storage",
"value": "[] check1"
},
"version": {
"number": 2,
"message": "v2.0"
}
}'
In confluence it looks like this.

Is there a way to display it correctly?