Treat the credential as exposed. Revoke or rotate it through its owning system, then update the applications that used it. Removing a screenshot is not enough to make a copied API key, session token, signing secret, or password safe again.
Tell support which kind of secret was exposed and when, without repeating its value. Ask about removing the unnecessary attachment from the support record. For suspected security exposure, contact [email protected]. Keep a safe record of the corrective action, and verify that the old credential no longer works.