Your certificate renews automatically. When it does not, the cause is nearly always a DNS record that changed without the certificate being reissued.
How renewal works
Your site runs on the Chek Digital Engine, so the steps below assume the standard configuration we hand over at launch. If anything on screen differs from what you see here, that usually means a custom workflow is in place — check with your account lead before changing settings.
When the padlock disappears
Tell us immediately. Browsers show a full-page warning for an expired certificate, so the practical effect is an offline site.