With iOS 13, we can add a reminder with official app using "natural input". For example "dinner at 19.00" will create a new reminder with an alarm automatically set at 19.00. BUT this is possible using the official Apple Keyboard, because when you type "at 19.00" the keyboard shows a suggestment over the first row, and if you tap on it the alarm is set automatically. BUT if you use SwiftKey, over the keyboard that suggestment doesn't show so the reminder must be completed manually.
A simple workaround is to use Swiftkey and official Apple keyboard together, swithing from one to the other when you need to write a reminder, but it is not easy and fast.
With the app DUE, basically with the same functionality, Swiftkey works perfectly.