I've tried making injera 3 times so far, the last time went best, but I struggled a bit with actually cooking them. Note that I don't typically make pancakes or crepes either, so my familiarity with their techniques is low. My recipe came from How to Make Ethiopian Injera- Ferment Teff Flour - YouTube.  No, it might not be very traditional, but that is not a big consideration for me.  I'll mention the overall idea, but prepping the batter went well enough:  2 parts teff, 1 of water bit of salt and yeast.  let sit 3 days. add 1 part flour (I subbed amaranth for wheat as one motivation for injera-making is gluten intolerance from my partner).  some water.  2 more days.  So, after 5 days I ended with a sourish-as-expected smelling injera and batter somewhere between pancakes and crepes that flowed easily. But this where things got challenging:  I don't have a non-stick pan - I prefer avoiding non-stick surfaces - and am instead using a cast iron pan, on a gas range. I slightly smeared some avocado oil to lessen sticking.  Experimented with various heats, from high to medium.  The video shows 360 on an electrical plate, so not sure what I am aiming for.   My main problem is achieving a "dry top". Injera is not supposed to be flipped.  While I can achieve something somewhat satisfactory on the bottom side, I found that the top remained rather wet and moist and I could not dry it out sufficiently without burning the bottom. Nothing I saw in this video or others really gave me any idea of how to do this.  If anything the video proposes covering the injera once it starts to bubble which would retain water. Should I?:  Use a lower temperature throughout and let it sit in the pan longer?  What duration should I aim for?  Try pouring the batter more shallowly?  I tried doing that but the cakes tore apart upon removal.  I had best results at about 4-6 mm (1/4").  Use another flour than amaranth?  My first tries were with pure teff and that didn't really work any better with regards to my "wet top" problem.  Have more or less water in the batter?  I am hesitant about this as the consistency did seem fairly optimal for pouring and spreading.  Remove it once it seems cooked at the bottom and let it sit for a few hours?  I found my injera improved significantly in that regard after a few hours.  They were quite good later, just not great at first.  Maybe that's just how it should be prepared?  I also tried removing them and finishing them off in the microwave for a few minutes.  Not entirely conclusive but it seemed to help a bit.  I tried covering.  And not covering.  The difference wasn't super clear - remember my problem is an overmoist topside so that wasn't intuitively obvious to me (but, yes, noted Esther's remark, quite helpful).   I was pretty happy overall and would like to continue experimenting.  Still I would welcome any tips on bettering my cooking technique. 
As commented by @Esther, covering cooks the top (by steaming it, pretty much) and that is the solution to your "wetness on top", which is raw dough, even if you find that counterintuitive. I happen to pan-fry all sorts of dough & batter things and covering definitely helps to cook more evenly (also works for a non-Julia-Child-approved slow omlette process to cook the top.) The "retained water" from covering it when it starts to bubble is steam and steam will transfer heat to the top of the food if you don't just let it escape. After it has cooked, you can uncover the pan to dry some, if needed. 