with my serial number check lock status

Hey there, and welcome to Apple Support Communities Veshe,

From our understanding, you would like to know if you can check your lock status with your serial number. We can certainly understand your concern and see you came to us from the article How to use Sign in with Apple.

We would like to ask you a couple of questions in order to get a better understanding. First, are you referring to Activation Lock on your device? If so, then we recommend checking out this link for more details on what to do if your device has Activation Lock enabled: Activation Lock for iPhone, iPad, and iPod touch - Apple Support

If not, can you give us more details on what type of lock status you are inquiring about?

Please keep in mind a phone can't be locked or unlocked with the serial number, nor can you check the status. You will need to contact your carrier for more details on if the IMEI has been flagged by your carrier for any specific reason.

We thank you for your answers, they will help guide us to the next troubleshooting step.

Kindest regards!