estos provides the ProCall Enterprise mobile apps only as long as the ProCall version is still in its life cycle.

After the end of life of a ProCall Enterprise version, the mobile apps can no longer be used.

In particular, this currently affects the ProCall Mobile App from ProCall 6 Enterprise (End of Life 2022).

To use the mobile app, it is necessary to upgrade the ProCall Enterprise version to a current version.
More information about current ProCall Enterprise versions can be found here: Product life cycle