@Kiriru
And os4depot or google as one may answer, but not me :) So:
https://os4depot.net/share/library/misc/qt-minimal.lhaBut be sure it's all .. well.. imho not what one need to use now. It have it's glitches, it's sobjs-hell bloat (a lot of bloat). And not everything supported. But it was more or less tested years ago by us so to be at least working somehow.
Alfkil (same author who do qt4 port) also made a QT6:
https://github.com/elfpipe/amiga-qt6But as far as i aware, it unfinished, may have bugs, works over clib4 specific versions (i can't be wrong there, but not sure if it will works as it over last one), and probably have the same bloat sobjs.
If you trying to choose what GUI toolkit to use for amigaos4 , then QT for sure not the right choose. It can be ok for some "fast ports" if need it, but in age of AI, it for sure better to rewrite QT stuff to Reaction or to MUI where need it , even with some limitations, and be done with it : faster, better, well-integrated result.