Thank you guys a lot for your support.

So if someone bricks his OPO so hard that he cant actually enter neither to fastboot or recovery then he can try this method.
Use ubuntu in a pc and then try to install ubport for OPO. At first the app will say that it cannot detect any device in fastboot mode and thats okay because after that you will be able to enter in fastboot.
After that you have to be sure that you PC is able to detect your device with fastboot commands even if it can't be showed in device manager. In my case i could see my device by typing fastboot devices.
And the final step is to flash the stock rom with fastboot commands.
So it seems like you cant flash ubports with windows OS but only with ubuntu otherwise your phone will be probably bricked.
Anyways thank you guys so much for your support and i hope this forum will help anyone else with the same problem i had with this device.
P.S: sorry for my bad english.