I think there is a misperception about what bribery is. See 18 U.S. Code §201.Bribery of public officials and witnesses

Quote
Whoever -
....
(2)being a public official or person selected to be a public official, directly or indirectly, corruptly demands, seeks, receives, accepts, or agrees to receive or accept anything of value personally or for any other person or entity, in return for:
(A)being influenced in the performance of any official act;
(B)being influenced to commit or aid in committing, or to collude in, or allow, any fraud, or make opportunity for the commission of any fraud, on the United States; or
(C)being induced to do or omit to do any act in violation of the official duty of such official or person;

Noting, of course, that the framers intended the term far more broadly, nonetheless all the elements are present: Zelensky said, "We are ready to continue to cooperate for the next steps specifically we are almost ready to buy more Javelins [anti-tank missiles] from the United States for defense purposes."

"I would like you to do us a favor though..."

The "ask" alone is explicitly bribery. Whoever "seeks"; a "thing of value"; "in return for; "being influenced in the performance of any official act".

I would like... (seek)
Pivotally it was "of value" because he asked for it
And he held up appropriated funds in violation of statute to enforce the "get"