Answer:
NH3 would be my best guess
Explanation:
"NH3 is a covalent bond. This is because, Nitrogen and Hydrogen have shared the electron. The main difference between an ionic and covalent bond is ionic bond will donate or accept electron."
source: https://www.quora.com/Is-NH3-an-ionic-compound#:~:text=NH3%20is%20a%20