What is the structure to update the sdk26 to sdk28 in ionic v1

ionic-v1
1

I’m using ionic version1 with sdk27 ,now target to sdk 28, my cordova version 8.1.2
Installed platforms:
android 8.1.0
Available platforms:
browser ~5.0.1
ios ~4.5.4
osx ~4.0.1
windows ~6.0.0
I’m unable to install app even build is success