<t>Please take a look at this article on how to set log level for function v1 or v2.<br/>
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In the file host.json, for the filed "Function", set its value to Trace. Then LogTrace() can be logged into application insights.<br/>
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Sample host.json for Azure function v2, which can log trace messages to Application Insights:<br/>
<br/>
{<br/>
"version": "2.0",<br/>
"logging": {<br/>
"fileLoggingMode": "always",<br/>
"logLevel": {<br/>
"default": "Information",<br/>
"Host.Results": "Error",<br/>
"Function": "Trace",<br/>
"Host.Aggregator": "Trace"<br/>
}<br/>
}<br/>
}<br/>
<br/>
```<br/>
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And if you publish your function app with visual studio, you can modify your host.json file as per the above before publishing.<br/>
<br/>
And if you want to change the log level in azure portal, please follow this:<br/>
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In Azure portal, navigate to your function app -> in the function app settings, make sure enable the Read/Write, then change log level to trace in the `host.json`.<br/>
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[](https://i.sstatic.net/VBHN4.jpg)</t>