Can you please verify requirements.psd1 file and verify what az module version is defined?
As per the error message the Set-AzOperationalInsightsSavedSearch was found but the command doesn't expect the parameter name as 'FunctionAlias'.
Looking into the document for Set-AzOperationalInsightsSavedSearch the parameter FunctionAlias was added in the az module 4.8 and above. The latest Az module is 5.0.0 so the requirements.psd1 should have 4.8 or above module to run the Set-AzOperationalInsightsSavedSearch with FunctionAlias parameter.
requirements.psd1
@{
'Az' = '5.*'
}
Feel free to get back to me if you are still facing the issue.
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