At last I found solution!!!
No wheel, no problem!
Step by step:
1. Turn off PS5.
2. Disconnect Thrustmaster T300RS wheel from console.
3. Unmount T300R wheelbase, pedals (in may case Thrustmaster T-LCM) and any other accessories (like handbrake) etc. from rig.
4. Clean carefully (not using any strong alcohol-based liquids) wheel, pedals, hanbrake etc. *
5. Search for boxes (hopefully you can find original boxes for your wheel, pedals, handbrake) etc.
6. Take a time and put all your stuff into original boxes and seal with tape.
7. Open your computer or phone or tablet.
8. Open web browser and got to ebay.
9. Log in (or if you don't have ebay account - create one) and put your T300RS, T-LCM and all other stuff on sell.
10. Return to your racing rig.
11. Turn on your PS5 console.
12. Make sure your PS5 controller is charged (or make sure your PS5 console is close enough to your rig, so that you can play with wire controller).
13. Select from main menu on top of your PS5 console game called "EA Sports WRC" and voila - youre good to go, problem with T300RS solved! Forget T300RS and play with PS5 controller!!! Works 100%!!!
* 4.5 - after cleaning it is good idea to make lot of pictures (with your phone for example) - you need them later, look at no 9.