Does using a pirated design program to create a video for a competition with financial prizes fall outside the scope of permissible personal use? And if it is impermissible, is it obligatory to pay the subscription fee for the previous period or only for the upcoming period?

Using the program to participate in a competition falls under personal use. The opinion that permits the use of pirated software for personal benefit is considered valid by some contemporary scholars. However, the fatwa (religious edict) that is relied upon is the absolute prohibition. The transgressor must pay the owner the value of the benefits they lost and the harm they incurred. This value is estimated by experts, or one should strive to estimate what absolves their conscience. If they cannot deliver the right to the company, they should donate it to the poor and needy.

The matter here is less severe because the program has a monthly subscription. Therefore, one can pay the subscription to its owners to make its future and past use permissible.