Forgetting the PIN of your phone can be a frustrating experience. Fortunately, there are a few things you can do to unlock your phone if you can't remember the PIN.
First, try entering the wrong PIN multiple times. After a certain number of incorrect attempts, your phone may prompt you to enter your Google account credentials or your device's factory reset option. If you remember your Google account credentials (email and password), enter them to unlock your phone. If you don't remember them, proceed to the next option.
Another way to unlock your phone is to reset it to its factory settings. However, this will erase all data on your phone, including photos, contacts, and apps. To reset your phone, turn it off and press and hold the power button and the volume down button simultaneously. Release the buttons when you see the recovery menu. Use the volume buttons to navigate to the "Factory reset" option and select it using the power button. Wait for your phone to complete the reset process.
Lastly, you can contact your phone's manufacturer or service provider for assistance. They can provide you with options to unlock your phone or help you reset it.