Currently we are working with OpenStack Rocky release. In this(i.e. OpenStack Rocky) Identity APIs with version v2.0 are removed (refer to following link https://docs.openstack.org/keystone/rocky/contributor/http-api.html).
I noticed that in APPC log Identity API with version v2.0 is using, As v2.0 is not available in OpenStack Rocky release, we are getting 404. please find the below log(also attached log).
Request to let me know how to use Identity APIs with v3.
 
2020-06-01T08:11:13,228 | INFO  | appc-dispatcher-10 | Keystone                         | 482 - appc-iaas-adapter - 1.6.4 | 1 * Sending client request on thread appc-dispatcher-10

_1 > POST http://192.168.9.75:5000/v2.0/tokens_
1 > Accept: application/json
1 > Content-Type: application/json
{
  "auth" : {
    "tenantName" : "admin",
    "passwordCredentials" : {
      "username" : "admin",
      "password" : "********"
    }
  }
}
 
2020-06-01T08:11:13,249 | INFO  | appc-dispatcher-10 | Keystone                         | 482 - appc-iaas-adapter - 1.6.4 | 1 * Client response received on thread appc-dispatcher-10
1 < 404
1 < Connection: Keep-Alive
1 < Content-Length: 233
1 < Content-Type: text/html
1 < Date: Mon, 01 Jun 2020 08:11:13 GMT
1 < Keep-Alive: timeout=5, max=100
1 < Server: Apache/2.4.29 (Ubuntu)
1 < Vary: X-Auth-Token1 < x-openstack-request-id: req-83c06e79-8f3c-403d-aa2e-c056452fed0b
 
Regards,
Manjunath.