I agree that this is confusing, Liz. It sounds like the male voice on Duolingo pronounces the 'ir' at the end of escribir differently than does the female voice. The male sounds like 'eer' while the female sounds like 'eed'. I think the female voice is more accurate as to how this is supposed to sound.
Your sentence is wrong, "poder" is not used this way.
It's a transitive verb, and is used this way:
poder as the first verb, conjugated, and a second verb following it, and not conjugated (infinitive mood)
"Poder" is sometimes the equivalent of "can".
But it's a verb, absolutely not a modal particle like "can" in English.
(Yo) puedo leer.
I can read.
"Necesito poder" would make no sense as it would be "I need can"