curl --location --request POST 'http://127.0.0.1:6810/api/activities/1/pilots' \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data-raw '{
"callsign": "string",
"aircraft_type": "string"
}'{
"code": "SIGNED_ACTIVITY",
"message": "报名成功",
"data": true
}