If you want to cancel online recruitment, you can log on to the National Recruitment Network, and you can usually find the option of "male soldier registration" in official website. Then, enter the user name and password and log in to the system. On the login page, find the "Register" option, and then click Enter. Then, at the bottom of the page, you can find the option of "applying for extension" and click it to cancel. If it has been determined by the local military service authorities as a pre-requisition object, you can also inform the township armed forces department where the household registration is located and cancel the pre-requisition qualification, and then follow the above process. These steps vary from region to region, so it is recommended to consult the local recruitment department for more accurate information and guidance.