Trying to cancel a subscription, but CANCEL button is not coming up on screen with other choices

See the following from How to cancel a subscription from Apple - Apple Support

 If you don’t see Cancel Subscription, then the subscription is already canceled and won't renew. 

and

If you cancel a paid subscription, you can keep using the subscription until the next billing date.

See the following from the Robokiller support site: https://support.robokiller.com/hc/en-us/articles/360027065591-How-can-I-disable-RoboKiller-on-my-iPhone-or-Android-device-