Out of the box, WordPress is very restrictive regarding the different types you can upload. The .cvs file type is one of the restricted file types.
The Chart module can create charts based on your manually entered data or based on the content of a .cvs file.
Install and activate the File Upload Types by WPForms plugin.
Go to Settings → File Upload Types.
Drag and drop the .cvs file into the Add Custom File Type box.
Click the Save button.
Make sure that the .cvs file remains enabled in the Enabled section.
