If it’s not growing, lack of light is probably one of the main factors (there can be many others, but let’s focus on this first).

People may think their plant get lots of light as it seems bright to them, but the plant usually doesn’t see it that way.

Right up in front of a southern facing window (if in the northern hemisphere) that’s unobstructed by blinds, trees outside, buildings, etc, would be the best spot. Yes, receiving “direct” sun. That sun is being filtered by the glass and is actually not direct.

Your only concern would be if you have no airflow in your house. Heat from the sun can be an issue. The smallest of fans keeping the air moving in the room is all you’d need.

This isn’t the best time of year to hope for good looking growth. While these plants never go dormant and will grow all year, the days are getting shorter and the sun is growing weaker.

Your tree will put out its best growth from about april-August.

lastly, this section of the forum is for edible figs. Your Ficus Lyrata, aka Fiddle Leaf Fig is not one of those.