Technically, when using a bundler like webpack, the result will not make a difference with regard to the output of your bundling process.
That being said, dividing the packages in dependencies and devDependencies still helps you (and others looking at your package.json) to understand which packages are meant to end up being a part of the bundle created (dependencies), and which are needed to build the bundle only (devDependencies).
Just remember main principle:
-> If you need package in production put it into dependencies (most likely axios should be in dependencies in your case).
-> If you need package only during development, put it into devDependencies (e.g. unit-test libraries, which isn't needed in productions should be in devDependencies
Summary of important behavior differences: