Ring doorbell ios - No option to enable critical alerts.

I have read the [instructions](https://support.ring.com/hc/en-gb/articles/360039406772-Getting-emergency-alerts-in-Do-Not-Disturb-mode) to enable critical alerts for ios but my phone does not have that option in the ring apps notification settings. In case you are unsure what, critical alerts are, they are notification that bypass the do not disturb function of the phone. I am running an up-to-date iOS 14 and have the ring doorbell 3. Has anyone else had this problem and know how to resolve it? Thanks Alan