Use Juju on top of OpenStack to deploy apps

I’d like to create a new cloud in JUJU for OPENSTACK and use that to deploy the Apps on my Instances. In my lab, MAAS, JUJU and OPENSTACK are correctly installed and the instancse works fine.
I’ve followed this guide but at the end during the bootstrap I receive this error:

ERROR authentication failed.: authentication failed

IP plan:

Network: 10.20.81.0/24
Maas: 10.20.81.1
Juju: 10.20.81.2
Openstack: 10.20.81.21-24
External Gateway: 10.20.81.254
Private Network: 10.1.0.0/24
Instance: 10.1.0.12 - 10.20.81.220 (floating IP)
Private Gateway: 10.1.0.1
Private DHCP service: 10.1.0.10

Network topology:

                          +-------------+
                              Firewall
                            10.20.81.254
                          +-------------+
                                 | 
+-------------------------------------------------------------+
                              Switch 
      vlan81              vlan81                  vlan81
+-------------------------------------------------------------+
        |                   |                   || | | |
+--------------+     +-------------+       +------------------+
|Maas+Juju           |Juju Gui|            |Openstack
|10.20.81.1          |10.20.81.2           |10.20.81.21-24
+--------------+     +-------------+       +------------------+
                                                     |
                                +----------------------------------------+
                                Private Subnet-1           Public Subnet-2
                                 10.1.0.0/24                10.20.81.0/24
                                 +---+----+--+              +---+------+
                                 |   |        +----+            |
                                 |   |     .1 |    |.221        |
                                 |   +--------+ VR +------------+
                                 |            |    |
                                 +--+-+       +----+
                                 |    |
                                 |VM |
                                 |.12 |
                                 |    |
                                 +----+

these commands have being launched on MAAS server, where I’ve installed juju,

   $:juju add-cloud
    Cloud Types
      lxd
      maas
      manual
      openstack
      vsphere

Select cloud type: openstack
    Enter a name for your openstack cloud: openstack-cloud
    Enter the API endpoint url for the cloud []: http://10.20.81.22:5000/v3
    Enter a path to the CA certificate for your cloud if one is required to access it. (optional) [none]: 
    Auth Types
    access-key
    userpass
    Select one or more auth types separated by commas: userpass
    Enter region name: RegionOne
    Enter the API endpoint url for the region [use cloud api url]: 
    Enter another region? (y/N): n
    Cloud "openstack-cloud" successfully added
    You will need to add credentials for this cloud (`juju add-credential openstack-cloud`)
before creating a controller (`juju bootstrap openstack-cloud`).

then

   $:juju add-credential openstack-cloud
    Enter credential name: richardsith
        Using auth-type "userpass".
        Enter username: admin
        Enter password: 
        Enter tenant-name (optional): 
       Enter tenant-id (optional): 
       Enter version (optional): 
       Enter domain-name (optional): 
       Enter project-domain-name (optional): 
       Enter user-domain-name (optional): 
       Credential "admin" added locally for cloud "openstack-cloud".

run the bootstrap

$:juju bootstrap openstack-cloud
ERROR authentication failed.: authentication failed
caused by: requesting token failed
caused by: Resource at http://10.20.81.22:5000/v3/tokens not found
caused by: request (http://10.20.81.22:5000/v3/tokens) returned unexpected status: 404; error info: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<title>404 Not Found</title>
<h1>Not Found</h1>
<p>The requested URL was not found on the server.  If you entered the URL manually please check your spelling and try again.</p>

opening that url on my browser I’ve: