First I cut the image into pieces each of which contained a single glyph and googled by image.
After 10 minutes of searching I found that those symbols are from Proto-Sinaitic alphabet (https://en.wikipedia.org/wiki/Proto-Sinaitic_script). So it's easy to recover latin letters from them symbol by symbol. I also found a great picture:


Recovered text: ```alphabetevolution```

And the flag is: ```ALLES{alphabetevolution}```

Original writeup (https://github.com/eg-ctf/Chaos-Communication-Camp-2019).