I think it means you can only take the test one time. a single attempt = one try only

Hey Alex, So what they’re saying is: 1.) ‘achieve the required test scores.’ = get a passing grade or mark. 2.) ‘the required test scores set out in the table below’ = the grade you need to pass ( OR meet the standards ) is shown below. 3.) ‘the table’ is a way to organize important information. 4.) ‘in a single attempt at the test.’ = you only get one chance to take the test OR you only get one try at the test. ‘Single attempt’ means if you do not do good enough one the first try, you do not get to try again. So be careful and good luck I know you can pass! :)

Does it mean that only one try is accepted, that is not allowed to take another try to pass the English test?