How can I resolve the 'INVALID_SECRET_LOOKUP' error with a 'SECRET_FUNCTION_KEY_NOT_CONSTANT' cause in Databricks?
To resolve the 'INVALID_SECRET_LOOKUP' error with a 'SECRET_FUNCTION_KEY_NOT_CONSTANT' cause in Databricks, you need to ensure that the secret key is passed as a constant string expression in the second argument of the SECRET function. This error occurs when the secret key is not a constant value.

Here's an example of how to correctly use the SECRET function with a constant secret key:

```python
secret_value = spark.sql("SELECT SECRET('my-scope', 'my-key') AS secret_value")
```

In this example, 'my-scope' and 'my-key' are constant string expressions. Make sure to replace them with the actual scope and key of your secret.

If you're still encountering the error after ensuring that the secret key is a constant value, there might be an issue with the secret scope or key itself. You can check the secret's availability by using the LIST_SECRETS table function:

```python
secrets = spark.sql("SELECT * FROM LIST_SECRETS()")
secrets.show()
```

This will list all available secrets in your workspace. Verify that the scope and key of the secret you're trying to access are listed. If not, you may need to create or update the secret in your Databricks workspace.