How to make character spawed from PlayerStart walk in the right direction?

I have finished the “Setting Up Character Movement” turtorial and I still have some problems.One of them is like this:

If the PlayerStart actor dosen’t alined with the world direction , the character walks in incorrect direction.For example,if I rotate the PlayerStart actor to let its X point to the opposite direction of the world’s X, then the W key is to move backward.

How can I make the character move just relavant to his own XYZ no matter which direction his PlayerStart facing ?