POST /api/login/oauth/access_token causes nil pointer dereference panic

Hi all, why when the following request:

curl --request POST \
  --url http://casdoor.localhost:9876/api/login/oauth/access_token \
  --header 'content-type: application/json' \
  --data '{"grant_type": "token","client_id": "ca52da969e6c6d667788","client_secret": "***"}'

returns casdoor:runtime error: invalid memory address or nil pointer dereference

@deleted_user provide full call stack

subOwner = anonymous, subName = anonymous, method = POST, urlPath = /api/login/oauth, obj.Owner = , obj.Name = , result = allow
2024/05/24 12:54:06.757 [I]  (10.0.0.4: ) subOwner = anonymous, subName = anonymous, method = POST, urlPath = /api/login/oauth, obj.Owner = , obj.Name = , result = allow
2024/05/24 12:54:06.759 [C]  the request url is  /api/login/oauth/access_token
2024/05/24 12:54:06.759 [C]  Handler crashed with error runtime error: invalid memory address or nil pointer dereference
2024/05/24 12:54:06.759 [C]  /usr/local/go/src/runtime/panic.go:884
2024/05/24 12:54:06.759 [C]  /usr/local/go/src/runtime/panic.go:260
2024/05/24 12:54:06.759 [C]  /usr/local/go/src/runtime/signal_unix.go:841
2024/05/24 12:54:06.759 [C]  /go/src/casdoor/object/token_oauth.go:247
2024/05/24 12:54:06.759 [C]  /go/src/casdoor/controllers/token.go:219
2024/05/24 12:54:06.759 [C]  /usr/local/go/src/reflect/value.go:586
2024/05/24 12:54:06.759 [C]  /usr/local/go/src/reflect/value.go:370
2024/05/24 12:54:06.759 [C]  /go/pkg/mod/github.com/beego/beego@v1.12.12/router.go:897
2024/05/24 12:54:06.759 [C]  /usr/local/go/src/net/http/server.go:2936
2024/05/24 12:54:06.759 [C]  /usr/local/go/src/net/http/server.go:1995
2024/05/24 12:54:06.759 [C]  /usr/local/go/src/runtime/asm_amd64.s:1598
2024/05/24 12:54:06.759  [HTTP] http: superfluous response.WriteHeader call from github.com/beego/beego/context.(*Response).WriteHeader (context.go:240)

use latest version casdoor