Hello,
Please follow the steps below to do the checking:
1. Check whether the AP is getting powered on correctly. (The switch indicator is on if the AP get powered on correctly)
2. Check whether the AP is set to the factory setting. (The IP address in the manual is the default IP address, if the AP had been configured, the IP address might be different, and you should reset the device to factory setting)
3. Check whether the CLI/HTTPS function has been enabled on the device.
BTW, If you can connect the PC to the AP, it's better that you directly connect the PC to the AP.