Hello Guys a question
I have CC2531 ordered. And i will use Hue bulb or Tradifri. What i only need is to convert my current switch on the wall that not get off, because if i do that by manually i can’t get switch on by HASS. I do not need to connect that switch to HASS (Just smart switch is not really needed for me) I need only that switch never get off but i will use it when needed to On/OFF manually. Which device or cable do need for that switch?
I will then configure only the bulbs by HASS.
I’m confused by your description.
I’ll tell you how I did it in my home with smart bulbs. The “normal” light switch is still there, but next to it I installed a Hue Dimmer Switch (you can us these with the CC2531 as well) and programmed them to control the lights. Now I told everyone in the house to only use the Hue Dimmer Switch to control the light. An advantage of this is, that when home assistant is down, you can still control the lights with the normal switch.
This not an option for me, because the switch are there and peaple use that. There may be really a solution to convert current switch…
Educate them not to use the normal switch but only the Hue Dimmer Switch 
You can also cut the connection to the normal switch so that the light will always stay on, but then the switch is useless.
Maybe you should rather use a smart switch than smart bulbs. A smart switch replaces your normal light switch and allows you to control it via home assistant as well.
Your second option is for me a good choice i thing.
In this case is that for me a good choice? https://www.aliexpress.com/item/4000046243169.html?spm=a2g0s.9042311.0.0.4a014c4dg4NGMO
But how can i connect the cables after the current switch to this unit?
Yes exactly something like this. Can’t give you any advice on which exact model you need etc. or on how to connect it, sorry.