Fastled library

How can I use the fastled Library with Uno Wifi Rev 2?

I cannot compile my sketch because the pin connections in Fastled settings are different or something like that.

I see you're already aware of this issue report:

I think that's the best answer we can give you.

The library doesn't currently support the Uno WiFi Rev2. The library authors don't seem very motivated to add support. The best bet is for some community member to do the necessary work and then submit a pull request to the FastLED library. Hopefully that will happen soon.

Although the Arduino system is designed to offer the highest level of compatibility between different architectures, in some cases you will find that libraries or sketches contain architecture-specific code that must be updated to work with a different board. For this reason, the community support for new Arduino boards takes a little while to catch up. You will find the best support for the AVR boards simply because they've been around the longest. For someone who enjoys challenges and wants to make significant contributions to the Arduino project, the new hardware is a great choice. For a beginner who just wants things to work immediately with the minimum of complexity, it may not be.

I see..

Is there an opportunity to use Fastled with the Rev2 or other librarys to control WS2812b Leds?

I've already explained the situation with FastLED. You can fix it or you can wait for someone else to fix it. If you are going with the latter option, I recommend you make sure you have your GitHub notifications enabled. Then you will get notifications about progress in the issue report you commented on and you will know as soon as the library has Uno WiFi Rev2 compatibility.

The other popular library for WS2812 is the Adafruit Neopixel library. You might give that a try: