Turbo tax is asking for my drivers license number when I enter it the system tells me it should be letters and numbers there are no letters in my drivers license number

Please enter the license number and use any numbers and/or letters but do not enter any special characters such as - or *  or spaces. The message is trying to stop the entry of any special characters or spaces and several states do have only numbers. Please be sure there are no extra spaces at the beginning or the end.