Different people asked about this song from Descendants 3, so enjoy your request! I thought it would be interesting if Amber sang this to herself as she remembered every time she did something bad, and she's especially paying for it now that she knows that Princess Ivy's coming is her fault, since she stole Sofia's amulet. Descendants 3 is not mine.
Amber: Here you are alone, and you deserve it
Your friends have turned to stone
And that's on you
You had a cause to serve but did you serve it?
Or did you see yourself in a way that wasn't true?
(as she thinks about how she acted when Sofia first came) This is not your father's fairytale
And no, it's not your mother's fault you fail
So when your story comes to light
Make sure the story that they write
(when she and Sofia meet Rapunzel) Goes once upon a time a girl tried harder
Once upon a time she tried again
Once upon a braver choice
She took a risk
She used her voice
And that will be my once upon a time
This time
(when she learns what Princess Ivy's motives are) Why tell all those lies?
You feel unworthy
Like there isn't solid ground for you to stand
But a stack of lies is not a firm foundation
You cannot build a castle on a mountain made of sand
(when she hears the maids giving Sofia compliments before her debut ball) This is not your mother's dark desire
And no, it's not your father's hair on fire
Turns out it's you who's not awake
So if there's change you wanna make
(as she recalls the talk James gave her before Sofia's debut ball) Take once upon a time she fought a dragon
Once upon a time that beast was me
Once upon a misspent youth
She faced herself
She spoke the truth
That's how I see my once upon a time
This time
(as she thinks about how she caused trouble during Sofia's Mystic Isles Protector mission) Life is not a storybook but life unfolds in chapters
Turn the page and start to make amends
There's no pre-written guarantee of "happily ever after"
Step into your greatness before your story ends
So when your story ends
(as she flies on dragons with Rapunzel) They'll say once upon a time a girl flew higher
Once upon a time she made things right
Once upon a tie that binds
She changed her heart
To change their minds
That's got to be my once upon a time
(just before she jumps in front of Sofia and gets zapped with a dragonfly) This once upon a time
I'll finally see my once upon a time
This time
