You can't. YOu tested positive. YOu're lucky they are offering you an extension of PTI and not sending you back to the trial calendar to face the distribution charges. If you stay clean you should be released early, but you are going to have to do the extension. And you should be thankful for the opportunity.
I agree with my colleagues. Based on your positive test, you were lucky to be given a second chance to complete the program.
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