I only catch 2-3 skunks a year and I thought about trying to save the quil for my own use.. so Can I store skunk essence in a canning jar with the rubber seal lids? Do I have to add anything to preserve it? Or is it just fine in a jar with nothing added ?

No on the canning jar. The essence is pretty corrosive and will eat the rubber and rust the lid pretty fast
I use glass whiskey bottle with plastic lid
No preservatives needed

Thank you for your help! Would a jar from a trapping supply work with plastic lid?

Yes sir is right. Any hard plastic cap will work, just make sure to keep the cap tight on the bottle or it will escape.

Dipping the lids in wax, or vacuum sealing the bottle in a vacuum bag after filling will help prevent the essence from escaping and permeating the room where it is stored.

I use 1oz. And 4oz. Bottles with plastic lids for long time storage. I then tape or dip wax the top on them store inside a quart mason jar