Help bypass security manager forgot administrator password

I've tried troubleshooting myself by looking online and tried every way i could find but nothing is working. As soon as my laptop is powered on it goes to a Dell security manager. It's asking for an administrator password and I have no clue what it is. My nephews where using it over the weekend when I had babysitting duty with them and today is the first time I'm using it after they were on it now I can't get on my laptop....please help me bypass it. I couldn't even access the safe mode or the one-time boot menu😮‍💨