In order to receive a postponement of the draft during mobilization, if there are conditions for this, you need to submit an application for a postponement and attach documents to it that confirm that you are really not subject to the draft.
In order to receive a postponement from mobilization in wartime, you need to appear at the TCC and SP in person to submit an application for a postponement from mobilization and go through all the necessary mobilization procedures. This means that you will have to update your military records and undergo a medical examination to determine eligibility. Only after that, if the documents are correct, can you get a postponement of the draft.