That being said, here are some methods to potentially obtain a free Threema License Key:

Designed for companies, this version uses a different licensing model for bulk users. Are There Any Legitimate Ways to Get Threema for Free?

Since Threema's business model relies on direct sales rather than data harvesting

Using a "cracked" version of a security app is a contradiction. If you use a modified version of Threema from a third-party source, you have no guarantee that the is intact. The person who "cracked" the app could easily have inserted a backdoor to monitor your messages. How Threema Licensing Actually Works

Below is a blog post exploring why these "Extra Quality Free" keys are a major security risk and what your legitimate options are.