Did you read the instructions at the odt plugin wiki page, and apply these to your export setup?
See
https://www.dokuwiki.org/plugin:odt#templates_support
Could you provide example syntax and an example of the template file?
If you think it is an issue with the plugin, you may report it at its tracker:
https://github.com/LarsGit223/dokuwiki-plugin-odt/issues (If reporting an issue, please include samples of template and content that you tried.)