It seems like the document number is not matching according to the E-invoice portal regular expression.
We request you to please change the invoice serial number according to the below instructions.
Must start with a letter or a digit between 1-9.
Can contain up to 15 more characters (letters, numbers, hyphens, or slashes).
Total length of invoice serial number is 1 minimum and 16 maximum characters.
Cannot start with 0
Cannot start with special characters like !, @, #, $, %, ^, &, *, (, ), -, _, =, +, {, }, [, ], |, , :, ;, ", ', <, >, , ., ?, /