A string dropdown selector for an input axis, plus an "Open Input Manager..." option to directly open "Input Manager" tab from "Project Settings" window where you can change input axes.

• AllowMultiple: No

using SaintsField;

[InputAxis] public string inputAxis;

It can work with ShowInInspector

[ShowInInspector, InputAxis]
private string ShowInputAxis
{
    get => inputAxis;
    set => inputAxis = value;
}

It can work with ShowInInspector/Button parameters and return value

[ShowInInspector]
private string ShowInputAxis([InputAxis] string myInput) => myInput;

[Button]
private string ShowInputAxis([InputAxis] string myInput) => myInput;