Hello,
Please let me know which methods you have already tried and what results you got, so I can avoid repeating the same steps. Thank you.
Open Device Manager and check if there are any devices with a yellow exclamation mark. Make sure the phone driver is installed correctly.
In most cases, the issue is with the connection cable. It might be just a charging cable rather than a data cable. To verify whether the cable is the problem, try using it to connect another phone and see if the computer can recognize it.