Trusty TEE implementation

I am currently working on banking app in Android(native development with Java, JNI but not in PhoneGap, ionic etc.). I have search a lot but did not find any tutorial for the same.

trustonic: very very expensive

for Trusty TEE but not understood how to use it and where to use?

Question:

1. How to communicate with trusted application?
2. How to install trusted application to trustzone OS with client application?
3. what will it need to implement(like libtee)?
4. is there any example available? if yes please provide the same.
5. How Trusty APIs call and if we need to do modify in code how to do that?