The ST-Community Installer is an app where the developer is no longer active on the platform. It is also a groovy smartapp so it will also cease when ST ends support for groovy on the ST platform so double whammy!
I do remember there were two options…external or though the ST app so you may want to try selecting the other option if you haven’t already tried.
below is the link to the app thread so you may want to scan through it to see if there are other solutions.