flutter error FormatException: Invalid radix-10 number (at character 1) code example

Example 1: formatexception: invalid radix-10 number (at character 1)

The mistake was stupid. I did not convert the controller to text. I directly did from controller ==> String. I am keeping this question just in case anybody else has a similar query.

Example 2: I/flutter (24560): FormatException: Invalid radix-10 number (at character 1)

// for Flutter, you need two parameters, in first you need to enter domain, and in second pass the subroute
var response =
          await http.get(Uri.https('favqs.com', '/api/quotes/4'), headers: {
        'Content-Type': 'application/json',
        'Authorization': "Token token='xxxxxxxxxxxxxxxx'",
      });