Yes, it must grow more branches and leaves for the trunk to thicken up. To do that it needs more light, heat and humidity. Best way for you to provide those is to move it outdoors for the summer into a semi-shade spot, eventually giving it 4 to 6 hours of sun at least.

Outdoors the higher light levels will often trigger a lot of dormant buds into growth along the branches and trunk.

Thanks Dave, I’ll move it out. Does it need to be acclimated or can I just pop it out back?

I live in Kentucky in an apartment and I'm have mine where they get full morning sun and minimal afternoon sunlight even though they are just seedlings

Looks beautiful. Has a nice shape. Everything grown in a greenhouse (or indoors) needs time to harden off and adjust to strong sunshine. Even greenhouse grown cactus will get a sunburn if they go from greenhouse to direct sun. My citrus face south and are underneath an umbrella. Citrus nurseries use shade cloth to protect container grown citrus. Keep an eye on the ceramic pot. Measure the temperature of the pot with your hand. If it warms up too much your plant will be in distress. Put it in the shade for a few days, than semi shade and so on. If the plant gets too much sun the leaves will start rolling over or turning away from the sun to block photosynthesis. First signs of sunburn are a mellow green color to the leaves, than brown.

and I got my seedlings in a pot of in the parking lot just next to the building

stick it outside

You must acclimate it slowly to sun or it will sunburn.