[Vuejs]-Cancel subsequent axios api calls, keep the last

I think your hunch that doing a call for every character being wrong is correct. You really should either verify on post that the entry is unique, and if not tell the user. If you want more real time feedback, you could send all the current entries from your DB once on page load, and loop through that on the front end (still not a great solution)

if you are married to your idea, you could solve it as follows:

Generate a unique id for each call and include it in your request.
when you make the call, save that id to a variable, something like lastCall.
Every call you make will update the id of last call. Then, when you start getting responses, you only need to react to responses that contain the same id that its in lastCall.

Again, I would recommend changing your approach, but this solution will help fix the issue of calls coming in out of sync. You will still be spamming your backend though.