How to use photutils.ellipse.fit_image() to fit the profile of Low surface brightness galaxy

I have a low surface brightness galaxy.
The maximum pixel value is 0.39, the minimum pixel value is -0.32.
Then I use photutils.ellipse.fit_image() to fit the galaxy. There is a warning.

AstropyUserWarning: No meaningful fit was possible.

I can't get a real fitting.
```[tasklist]
### Tasks
```

Start at the photutils.ellipse.fit_image() entry point and investigate the reported AstropyUserWarning using the image and pixel range provided. The issue does not identify a source file, test, fitting parameters, or reproducible dataset, so first determine whether the warning reflects expected behavior or a fitting defect; done requires a reproducible conclusion and an appropriate regression test or clarified usage guidance.

Written by the indexing model from the issue text.