Check the link below to see the LCB's required permission process for retesting. They include a link on the page that shows you the allowable ranges of test results for retesting for various products and uses. That might help you determine what to do, or what your next question is.
If you have the COA, you can determine why the first test failed. Some fail results make the lot ineligible for a re-test, like any trace of E. coli or salmonella. The bile type of bacteria can also be a problem if it is over the limit. You can always appeal to the LCB if you think you can remediate the issue or if you think there was some error in the sample handling.
If you've already received permission for the retest, you can remove the current QA result from the inventory in GrowFlow and then submit the product for QA testing on a new QA order. For steps on how to remove a QA result, see the "Modify Special" section of the article WA Standalone: The Modify Tool.