how can i fix this to run command: Command Inactive - No VALID Cert Code Detected
seagate st380215as?

Find the cause first... I bet you had the wrong suggestion and the result is a broken drive.

yes the wrong suggestion

I think you have to go to the person who gave this suggestion and say "and now you bring my data back" or - if you said the truth about data importance - "now you bring my drive back to life no matter the data inside". If it was you with DIY, accept the loss and get a new drive as it is not possible to help you in the forum nor in private.

If you were here it would have been a few $/EUR repair with loss of data (just repair the drive) . I'm quite sure you started something like "N" command, right ? (if so, kiss your data goodbye).