You can get information about a user's current brute-force status using the admin REST API GET /admin/realms/{realm}/attack-detection/brute-force/users/{userId}.
https://www.keycloak.org/docs-api/26.1.5/rest-api/index.html#_attack_detection

You will get those data :

{
    "failedLoginNotBefore": 0,
    "numFailures": 0,
    "numTemporaryLockouts": 0,
    "disabled": false,
    "lastIPFailure": "n/a",
    "lastFailure": 0
}