Typo - lower-case letter

[M507]

ERROR! the role 'LogStash' was not found in /root/Alert/SIEM_Server/roles:/root/.ansible/roles:/usr/share/ansible/roles:/etc/ansible/roles:/root/Alert/SIEM_Server

The error appears to have been in '/root/Alert/SIEM_Server/site.yml': line 8, column 9, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

      - ElasticSearch
      - LogStash
        ^ here