From the screen shots I've seen, it appeared that the keyboard on Jolla phone does not have keys like Ctrl, tab and esc. Is there more than one keyboard layout that comes with phone? On my Galaxy Note 3 I can do a Ctrl by pressing the lower volume. Then the combination: Lower Volume + i makes tab for example. Perhaps the Jolla phone does something like this?
Another possible option: Is the android app called hackers keyboard available to download from Yandex... This has all the control keys I mentioned as well as F1 and so forth.