Thanks in Advance
I assume you’re asking for mapping using the old Input Manager, using custom joysticks with that system is really difficult, you’re much better off using the new Input System.
Especially for custom joysticks it’s going to be really difficult to find those bindings whereas the new Input System should detect them all by default.
I made a tutorial covering the new Input System in detail here How to use NEW Input System Package! (Unity Tutorial - Keyboard, Mouse, Touch, Gamepad) - Code Monkey