Spyware on my phone

You cannot get it checked. All you can do is either restore it as new in iTunes or Finder (MacOS Catalina or Big Sur). Or go to settings, general, reset and select erase all content & settings. When the device reboots, set it up manually and do NOT restore from any backup file.

Erasing the device and setting it up again manually is the only way to remove malicious software.

And change your AppleID password and don’t give it out, to anyone for any reason.

The only way spyware could be installed is if someone had physical access to your device and a computer to connect it to, and time to install the spyware.

The only way it could be installed remotely would be if your AppleID password was known (and if you use 2 factor authentication, the person would also need access to one of your trusted devices to get a code) so someone could access your iCloud account. They could then install your backup to a separate device, alter the software on that device, then back it up to your iCloud account. You would then have had to restore your own device with that backup in order to install their hack. And if you use automatic iCloud backups, you’d have to do so within 24 hours of the hacker’s backup. Otherwise your own, un-corrupted system would get backed up and over write the hacker’s backup.

So unless one of those two scenarios is likely for you, then you do not have spyware.

And if you did, the only solution would be to erase the device by restoring it as a new device. Then set it up again manually - not using any of your own backups.