For an iPhone you own, Apple's supported route is to erase the locked device and restore it—not bypass the passcode. Depending on the iOS version and setup, use the lock-screen recovery option, Find My, or connect the iPhone to a trusted computer and place it in recovery mode. A recent iCloud or encrypted computer backup is the only reliable way to restore data afterward.
Activation Lock remains in place after erasure, so you must sign in with the Apple Account associated with the phone. If that account is unavailable, begin Apple's account-recovery process or contact Apple Support with proof of purchase. Do not give a remote stranger the Apple password, verification code, or computer access.
After restoring the phone, set a new passcode, review trusted devices and recovery contacts, enable two-factor authentication, and make a fresh backup. If it is a child's family device, configure Screen Time through Family Sharing with a separate parent-only Screen Time code.
Parental-monitoring products cannot lawfully unlock a passcode-protected iPhone or remove Activation Lock. Consider one only after ownership and access have been restored through Apple.