Should I stop working on the montage of da'wah clips if that requires the use of pirated software?

It is not permissible to use pirated software without the permission of its owners, even in the field of da'wah (Islamic proselytization). Those who do so must be advised to stop. An excuse may be granted to someone who has a fatwa permitting this action from a trustworthy scholar known for their knowledge and piety. As for the questioner, they should act according to their own conviction.