This will be the Plattdüütsch keyboard.
https://www.researchgate.net/publication/281581967_Low_German_A_profile_of_a_word_language/link/55ee91e208aef559dc43c3f9/download?_tp=eyJjb250ZXh0Ijp7ImZpcnN0UGFnZSI6InB1YmxpY2F0aW9uIiwicGFnZSI6InB1YmxpY2F0aW9uIn19