Oraciones usually means “prayers” in this context, although it can also mean “sentences” in Spanish grammar. The singer promises that the person will always remain in her prayers, giving the word a tender, spiritual meaning and making it more memorable than an everyday love-song term.
This is a farewell sung like a prayer. The opening lines come in almost spoken, like a voice note left for someone who is already gone: "Espero, pues, que si escuchas esto" [I hope, then, that if you hear this], "siempre vas a estar en mis oraciones" [you will always be in my prayers]. Before that she says "Yo sé que con mucho esfuerzo / Voy a poder conseguir todo eso que conté y que quería para mí" [I know that with a lot of effort / I'll be able to get everything I talked about and wanted for myself]. So she is moving on, but she is taking the old plans with her.
Then the chorus turns into two questions, and they hurt. "Qué te pedí" [What did I ask of you] answers itself: only "leal comprensión" [loyal understanding], and that you would know "no hay en la vida otro amor / Como mi amor" [there is no other love in life / like my love]. The second question, "Qué no te di" [What didn't I give you], flips it around: she offered everything she could "en tus manos poner" [put in your hands]. The best line is "Y aunque quise robarme la luz para ti" [And even though I wanted to steal the light for you], a huge, slightly over-the-top promise, which makes the flat ending land harder: "No pudo ser" [It couldn't be].
Learner tip: "pues" here is a filler, close to "well" or "so". "Tengas presente" means "keep in mind", and "No pudo ser" is the everyday Spanish way to say something just didn't work out.