I understand you are trying to remove the OmsAgentForLinux. You have tried doing so from the portal as well as other methods but still unable to.
You can try to use the purge method to remove the extension.
If that doesn't work you might try this option, Issue: You're unable to uninstall omsagent using the purge option.
Let me know if that doesn't work and we can troubleshoot with you directly.
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