Flashcards and ordered data are not immediately compatible. See SuperMemo inventor Piotr Wozniak's rules 9 & 10 of "Effective Learning: Twenty Rules of Formulating Knowledge": Avoid Sets and Avoid Enumerations.
But even though he advises avoidance he does provide a strategy at the bottom of rule 10:
"Learning poems is an example of learning enumerations (all words and sentences have to be uttered in a predefined sequence); however, due to strong semantic connections, the rhyme and the rhythm, it may often be possible to effectively remember poems without using cloze deletion and without the frustration of forgetting small subcomponents again and again. However, once you notice you stumble with your poem, you should dismember it using cloze deletion and thus make sure that the learning is fast, easy, effective and pleasurable"
A poem is a stream, and its order is part of what it is. When you first learn it, you need to learn it in order so you can establish all the triggers you will need along the way. Initially you will likely need to figure out your mnemonic cues, or perhaps make a memory palace. But then you have to drill it in the proper order for a period of time.
We can call this the Learning stage. Once it is learned, that's when Flashcards and spaced repetition can reinforce, sharpen and embed. Until it's Learned, the Learner needs it to be ordered.
There are techniques to account for this.
You could put the whole poem in one card. This is a sensible approach. To be able to correctly answer you need to be able to say the whole piece in order. Of course, this doesn't scale. We humans learn better when we can chunk it down.
You could use cloze deletions. This approach seems the most popular:
Card 1
[Twinkle twinkle little star]
Card 2
Twinkle twinkle little star,
[how I wonder what you are]
Card 3
Twinkle twinkle little star,
How I wonder what you are
[Up above the world so high]
Card 4
Twinkle twinkle little star,
How I wonder what you are
Up above the world so high
[Like a diamond in the sky]
This is great, but FSRS and spaced repetition will take these cards and shuffle them, scheduling them independently based on each card's stability. Spaced repetition and ordered cards are at odds.
Flipnem Review Cards Solution
There are two ways to do Reviews in Flipnem. The most common path is to start a Study Session. This tracks to the Anki 'Study Now' approach. The cards that are scheduled are played for you and you basically rely on the FSRS algorithm to "pick" the set and the order. The other mode (in Flipnem) is called a Review Session. This gives the user the ability to specify order and choose whether the cards schedule stats get updated during the session. This is perfect for the Learning stage of a Poem. If you play the deck as a Review Session, choose Natural Order, and Record the Session you will get to learn in order but will also get credit and can record each card's answer. You get your cake and eat it too.
Then once you feel like you have graduated out of learning phase, you can flip to standard Study mode. This way you'll only be getting quizzed on the cards that need it. Because that is the drawback of the Review Session approach, you will be spending time on every card (every line). So at first it makes sense. But after you got the order down then you can lean on the efficiency that FSRS brings to ensure that you've got it stabilized.