Use apple shortcuts to create a push button interface for your particle device. Pressing a button will generate a webhook and thus an event on the particle cloud. This event can be subscribed by your particle device to do your bidding.
open shortcuts and create a shortcut with "get contents of" URL.
Enter the following URL, authorization, name, data. Use your desired event name and data. Data can be a variable from your iphone.
For Authorization, enter Bearer XXXXXXXYOURTOKENHERE
Your token can be found here. Generate one with no expiration.
Once properly configured your event and data will appear in the particle console.