I used Audacity and export the file as .xml file.

Then I uploaded according to the instructions. What type of file did you save as? Maybe you can fix it.
Most people in this forum like to improve English. It doesn't matter whether your pronunciation is good or not, the resolution to better yourself is what counts more.
Below is a poem that my kid learned, which I think is very motivating.:-)

Try Try Again

by T. H. Palmer


‘Tis a lesson you should heed,
If at first you don’t succeed,
Try, try again;

Then your courage should appear,
For if you will persevere,
You will conquer, never fear