Search in cydia and find the app patch corresponding to the system version. After the installation is completed, you should be able to install ipa programs. If you want to install it on your mobile phone, you should install an Installous program and download and install it directly from cydia.
If the app patch has been installed, then: If you want to install it on your mobile phone, you should install an Installous program, which should also be downloaded and installed directly from cydia.
P.S. heard that installous was closed, and it was ok to change it to appcake. Installation method is the same as above.