According to the Hanafi school, Zakah is a pure act of worship, which requires intention at the time of disbursing it.  Therefore, they insist one is not allowed to take out zakah from his estate if he or she did not leave a will to that effect.

If, however, the heirs want to take it out on his or her behalf on their own that is allowed.

It is not, however, a must to do so.

In such matters, we also ought to take into account the general Islamic principle: everyone is responsible for his deeds. Allah says, “On that Day will every human being be requited for what he has earned: no wrong [will be done] on that Day: verily, swift in reckoning is God!” (Ghafir 40:17)

Therefore, as some scholars have said, “No one can pray for another or fast for another.”

However, it is true that since children are indebted to their parents, the Prophet (peace be upon him) allowed their children to pay the spiritual debts of their deceased parents even as they would be willing to pay their material gifts – as long as they are in a position to do so. It includes paying fidyah for their missed fasts or performing Hajj if they could not do so while they were alive.

In other words, it is not mandatory on your part to do so if they have deliberately neglected their duties.

Furthermore, your priority is to provide for your family and take care of the living.

If you have additional means, then you may volunteer to pay fidyah on behalf of your deceased parents.

Almighty Allah knows best.