Need xamarin app developer

Previous developer developed an app just over half of me, then a problem led the programmer to retire. I urgently need to finish this app. It is in c # developed with xamarin. I need complete Android and iOS app.

Here's app design
https://xd.adobe.com/view/a3ed9272-ab13-4763-abda-3648a1736655-f6be/?fullscreen

This is apk file of the app
https://drive.google.com/file/d/1EPTy5WIV9NWyFghnlsaPrkefEsCyC2ba/view?usp=sharing


the app already works
I have to complete the "combined" button in the training section
workouts are taken from the database. the table is called Trainings. Inside there is an Intersections column whose values are composed as follows:

first letter (1 character) represents the level and can be 0 (beginner), 1 (beginner), 2 (intermediate) or 3 (advanced)

second letter (1 2 or 3 characters) represents distance and can be S (sprint), O (Olympic), 70.3 (IronMan 70.3), IM (ironman)

third letter (1 character) represents the discipline and can be, N (swimming), B (bike), C (running) or K (combined)

fourth letter (1 or 2 characters) represents hours and can be 8, 12, 16, 20

Last letter (1 character) represents intensity and can be A (aerobic), M (medium), F (strength), K (for combined)

A value of the type 3IMK16K means that it is a workout for those who have selected these parameters:
Advanced
IronMan
Combined
16 hours
Combined

At the moment if you click on the "combined" button it doesn't work

I hope I was clear