Error installing wazo C4 engine for the first time

Hi everyone, I am a new user who would like to install wazo c4 to test and learn.
I have followed the initial indications of the page:
wazo-platform.org / use-cases / class-4

I have installed a machine for each element and generated the following configuration file following the instructions:

=================
#primer intento con wazo c4
[sbc_host]
sbc_1 ansible_ssh_host=10.0.51.11 ansible_ssh_port=22
sbc_2 ansible_ssh_host=10.0.51.12 ansible_ssh_port=22

[router_host]
router_1 ansible_ssh_host=10.0.51.31 ansible_ssh_port=22
router_2 ansible_ssh_host=10.0.51.32 ansible_ssh_port=22

[rtpengine_host]
rtpengine_1 ansible_ssh_host=10.0.51.21 ansible_ssh_port=22
rtpengine_2 ansible_ssh_host=10.0.51.22 ansible_ssh_port=22

[database_host]
database_1 ansible_ssh_host=10.0.51.41 ansible_ssh_port=22

[redis_host]
redis_1 ansible_ssh_host=10.0.51.51 ansible_ssh_port=22

[sbc:children]
sbc_host

[router:children]
router_host

[router_api:children]
router_host

[rtpengine:children]
rtpengine_host

[database:children]
database_host

[redis:children]
redis_host

[c4:children]
sbc
router
router_api
rtpengine
database
redis

[database:vars]
postgresql_listen_addresses = *

[router:vars]
router_api_db_host = 10.0.51.41
router_api_redis_host = 10.0.51.51
router_dburl_dialog = redis [at] 10.0.51.51:6379/2

[sbc:vars]
sbc_advertise_address = c4.wazo.cloud:5060
sbc_dispatcher_list = “1 sip:10.0.51.31:5060 16 10\n1 sip:10.0.51.32:5060 16 10”
sbc_dburl_dialog = redis [at] 10.0.51.51:6379/2

[sbc_1_host:vars]
sbc_advertise_address = 201.219.153.38
sbc_advertise_port = 5060

[sbc_2_host:vars]
sbc_advertise_address = 201.219.153.39
sbc_advertise_port = 5060

[rtpengine_1]
rtpengine_public_address = 201.219.153.40

[rtpengine_2]
rtpengine_public_address = 201.219.153.41

[c4:vars]
wazo_distribution = pelican-buster
wazo_distribution_upgrade = pelican-buster

and when executing the installation it gives me the following errors:

ansible-playbook -i inventories/c4 c4.yml

=============================
[WARNING]: * Failed to parse /root/wazo-ansible/inventories/c4 with yaml plugin: Syntax Error while loading YAML.
did not find expected The error appears to have been in ‘/root/wazo-ansible/inventories/c4’: line
3, column 1, but may be elsewhere in the file depending on the exact syntax problem. The offending line appears to
be: [sbc_host] sbc_1 ansible_ssh_host=10.0.51.11 ansible_ssh_port=22 ^ here

[WARNING]: * Failed to parse /root/wazo-ansible/inventories/c4 with ini plugin: /root/wazo-
ansible/inventories/c4:71: Expected key=value host variable assignment, got: 201.219.153.40

[WARNING]: Unable to parse /root/wazo-ansible/inventories/c4 as an inventory source

[WARNING]: No inventory was parsed, only implicit localhost is available

[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not
match ‘all’

PLAY [all] **********************************************************************************************************
skipping: no hosts matched

PLAY [database,router_api] ******************************************************************************************

TASK [Gathering Facts] **********************************************************************************************
fatal: [database_1]: UNREACHABLE! => {“changed”: false, “msg”: “Failed to connect to the host via ssh: root [at] 10.0.51.41: Permission denied (publickey,password).”, “unreachable”: true}
fatal: [router_1]: UNREACHABLE! => {“changed”: false, “msg”: “Failed to connect to the host via ssh: root [at] 10.0.51.31: Permission denied (publickey,password).”, “unreachable”: true}
fatal: [router_2]: UNREACHABLE! => {“changed”: false, “msg”: “Failed to connect to the host via ssh: root [at] 10.0.51.32: Permission denied (publickey,password).”, “unreachable”: true}
to retry, use: --limit [at] /root/wazo-ansible/c4.retry

PLAY RECAP **********************************************************************************************************
database_1 : ok=0 changed=0 unreachable=1 failed=0
router_1 : ok=0 changed=0 unreachable=1 failed=0
router_2 : ok=0 changed=0 unreachable=1 failed=0

=============================

I guess I am missing some steps, please help me with what I would be missing or a link with more detailed instructions.

Thanks
Jaime