I think you could try to go to Settings > Safety & emergency > Wireless emergency alerts and toggle off AMBER alerts. (that is the option on my Pixel  and Samsung).

As I am running the latest update of Android update, If that doesn’t work on your S9, you could try this https://www.lifewire.com/how-to-turn-off-amber-alerts-android-4689196

In Canada you can't turn off emergency alerts. They are all sent out at the maximum priority level of ‘presidential alert’, which cannot be silenced. Any instructions you find online for how to turn off emergency alerts will only work in the US, where they actually use different alert levels for amber alerts, weather alerts and system tests.

I believe the phone will only vibrate if it's set to do not disturb though.

Thank you both but either one of these work as I don’t have the settings and I can’t use silence on my phone at night and I use it to alert for medical needs

Have you checked the settings for do not disturb specifically? My phone, at least, has the option to select app notifications to let through, as well as the ability to allow calls or texts from specific numbers even while in do not disturb.

Fortunately, these amber alerts are not a dime a dozen over non-waking hours.