The answer is connected with the fact that God's omniscience, stemming from His existence outside of time, is not reduced to the mechanical predetermination of every choice we make.

Eternal Insight: Divine Omniscience and Free Will

The answer is connected with the fact that God's omniscience, stemming from His existence outside of time, is not reduced to the mechanical predetermination of every choice we make. God, being beyond temporal constraints, perceives the entirety of life as a single present, which is why He "sees" our actions as we perform them rather than deciding them for us in advance.

As emphasized in one of the sources, it is stated:
"From eternity, God is aware of everything that must be and that must come to pass in time. ... Therefore, ontological determinism in the presence of moral freedom is something entirely different from the causal predetermination of everything from eternity. In eternity, God predetermines only all the possibilities of what may occur in the world, but these possibilities are creatively realized by the moral freedom of man..." (source: link txt).

Another source explains that God's omniscience does not deprive man of his freedom of choice:
"God does not foresee our future actions as a human being might, but rather sees our deeds as we perform them. Moreover, our freedom suffers as little as that of our neighbors... Therefore, God either foresees them or sees that we execute them by our own will. Furthermore, He foresees not only our actions, but also their cause—our freedom." (source: link txt).

It is also noted that if one considers the concepts of time under the condition of God's timelessness, then for Him the past, present, and future merge into a single whole:
"Since we approach the question of predetermination in this way, we must first of all detach ourselves from the notion of time... That which we perceive as predetermination is, in reality, omniscience. Free will is in no way diminished by this." (source: link txt).

Thus, despite the fact that God exists outside of time and possesses knowledge of all possible events, this knowledge occurs without infringing on human freedom: we decide for ourselves how to act, and God merely "sees" these decisions, since for Him the entire temporal process is a single present. This means that predetermination, as such, does not dictate the inevitability of each of our actions, but rather encompasses all the possibilities provided by free will.

Supporting citation(s):
"From eternity, God is aware of everything that must be and that must come to pass in time. ... Eternity embodies the entirety of time... Therefore, ontological determinism in the presence of moral freedom is something entirely distinct from the causal predetermination of everything from eternity." (source: link txt)

"God does not foresee our future actions as a human being might, but rather sees our deeds as we perform them. Moreover, our freedom suffers as little as that of our neighbors... Therefore, God either foresees them or sees that we execute them by our own will." (source: link txt)

"Since we approach the question of predetermination in this way... That which we perceive as predetermination is, in reality, omniscience. Free will is in no way diminished by this." (source: link txt)