How to decode a large bytes synchronously (excel file)

I am using excel package version 2.0.0-null-safety-3 to read an excel file,

For small files, it looks good

But when reading a large file, the interface stops until the file is read

Excel.decodeBytes(_bytes);

decodeBytes method => sync is not supported

Is there a way to make the process synchronous

To be able to show the (download bar or waiting dialog) to the user

Thanks in advance.