This guide will let you know how to fix Free PS Plus Trial/Subscription Error WS-43689-0. Go through the guide and follow the instructions to fix it.
First, you have to click on the Subscribe Free button, taking you to the proceed checkout. After getting there, click on the Proceed to Checkout button located on the right bottom side of the screen.
After that, you will have to click on the Confirm button on the screen, and you will get the 14- days free trial of PS Plus.
For the next method, you have to go to your PS store, go to the Avatar tab and select the avatar. Add it to the cart, purchase it and then you will get the free 14-days trial of PS plus, as shown in the image below.