One would think so, but it doesn't have that meaning at all. There's a similar one that means 'this morning': i morse, but morse isn't used as an independent word that I can think of. (i går morse also works for 'yesterday morning')
Just want to say that imorgon is correct too. Same for idag, igår.
Even if writing it apart is recommended, as said below. Canät duolingo accept that version_
Språkrådet rekommenderar särskrivning, men accepterar även ihopskrivning.
Both are perfectly ok and are accepted when translating from English into Swedish. Unfortunately there is a bug that makes it hard for Duo to accept spelling variation in the listen and type exercises, so it doesn't work there.