Error: Please attach a font file before submitting the form.

I'm trying to convert a font, but I get an errror that I need to attach a font before submitting the form, even though I have a font attached

<img width="892" height="944" alt="Image" src="https://github.com/user-attachments/assets/6a2c3d80-261e-49e0-bf46-464f0e0c7842" />