This is very easy,
Step 1. Launch Cydia, search for AppSync Unified
Step 2. Install it. (now iTunes will let you sync any IPA to your phone)
(if search result doesn't show AppSync Unified do the following)
Tap on the "Manage" button.
Now tap on "Sources" button. Touch the Edit button and then tap on Add.
Now app this repo –> https://cydia.angelxwind.net/
Once the repo is added, tap Return to Cydia.
Tap on the newly added repo.
Search for AppSync Unified and simply touch it, then select "Install" to start the installation process.
Step 3.
Now sync your IPA to your phone using iTunes, Cydia Impactor or by opening the IPA using Filza.