Two subscriptions do not appear on my phone that I want to cancel.

Subscriptions are tied to your Apple ID, not a particular device.

If they don't show up in the regular place on the iPhone, make sure of the following:

1. The subscriptions were started on an Apple Device using the Apple ID currently used by the iPhone
2. If you are a Family Organizer in Family Sharing, the subscriptions may have been started by someone else in the family group so would appear on their account not yours even if you are paying for them.
3. The subscription may have been started on a non Apple device or directly on the provider's website, in which case it won't show up on your Apple ID.

Take a look at this. It’s possible that the subscriptions were purchased through the web or in the app itself.

If the subscription that you want to cancel is not listed - Apple Support