Happy friday all, is it possible to delete a journal without unlocking the period ( this is in admin role)

JE impacts GL, even with admin role you can't delete such transactions without unlocking the period first which could potentially impact the books.

You can reverse it in first open period after, note that deletion after the close is not only bad practice but downright illegal in a number of countries.

Compliance wise no JE should be deleted in closed period. To fix error just do a reversing JE in the next period as @PWN suggested. Technically admin should be doing any transaction as per compliance guideline

If the period is locked, yes you can delete. If closed, as others have said - no