Online OCR incorrect URL message

I joined to OCR API yesterday, I tried OnlineOCR first. When I select PDF file via 1.option-Upload image or PDF it works perfectly.
When I use 2.option-PasteURL to source file, I have got error
File validation error / File must have size greater than 0
When I use free API I have got another error
{“OCRExitCode”:99,“IsErroredOnProcessing”:true,“ErrorMessage”:[“Some internal processing error occurred. Please give us some time, we are looking into this!”],“ErrorDetails”:"","ProcessingTimeI
See my enclosed file
Many thanks for your advice, I am sure that is my incorrect parameters
Best regards Miloslav

Thanks for the screenshot. I answered here: URL for local files