You won't know you're forgiven, so continuously seek forgiveness
According to this IslamQA article:
You either perform the prayer as soon as you remember, such as you did, or if you deliberately decided not to pray then you must repent and seek forgiveness:
[If] He missed it for a reason, such as falling asleep or forgetting it. There is no sin on him in this case, but he has to make it up when he wakes up or remembers it.
It was narrated from Anas ibn Maalik (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) said: "Whoever forgets a prayer, let him offer it as soon as he remembers, for there is no expiation for it other than that."
— Narrated by al-Bukhaari (572) and Muslim (684); Muslim narrated an additional phrase: "or sleeps and misses it".
n.b. from my own studies with alkauthar, I was taught "there is no such thing as qaza (kazah) prayer". Do not fall into the trap of thinking you can (casually) make up prayers after their fixed time.