After five unsuccessful attempts at entering your PIN, password, or pattern, there'll be a Forgot PIN/password/pattern? prompt.
1Tap Forgot PIN/password/pattern?
2You will then be taken to the Reset with previous screen lock screen. Enter your previous PIN, password or pattern.
3You can now set a new PIN, password or pattern.
Or- plug into PC and factory reset the phone
Advice from reddit i found too
https://www.reddit.com/r/GalaxyS21/s/L5pHNA2qNo1. Find My Android through Google. You likely can't do anything with the lock, but you might be able to command a factory reset. This didn't work for me. 2. Try Find My Phone through Samsung. This one has several options, including setting a lock, unlocking, or factory reset. It told me I didn't have remote unlock enabled, so that option didn't work for me and neither did the factory reset (it needs to be able to remote unlock for that). Changing the lock didn't give me access either, so no luck there.
3. I thought I'd have to wait for the phone to die to force a reset, but finally figured out the following steps:
• Connect your phone to your laptop via usb-c cable. • Hold down both the power button and the volume
down button until the screen light goes off. • Continue holding the power button while you release the volume down and press the volume up button.
• As soon as the Samsung logo comes on, release both buttons and wait several seconds for the reboot screen. • Use the volume buttons to navigate and the power
button to select the factory reset option. • Next select the reboot option to power the phone back
on.
At this point you'll be asked to enter your wifi info as the system recognizes that it was an "unauthorized reset". You'll need to know your google account info to regain access to the phone, and will also need your Samsung account info. I was also asked to enter a code that was sent to my Samsung tablet, so if you don't have any other Samsung devices connected then unsure