@kservice you can use the geany IDE
https://www.geany.org/ but you must be aware that geany is a multi-programming-language IDE that
determines what compiler to launch depending on the file extension, for a *.bas file it will try to launch FreeBASIC also the highlighting is that of FB
you can write a small batch file that will launch qb64 and compile your program, substitute the fbc command with the name of your bat file
you must have a .bas file open in geany to adjust the menu settings for basic files because the menu settings vary depending on what kind of document is open, once you have a bas file open click on the Build->Set Build Commands in the Compile box you will see something like
fbc -w all "%f"
you could replace fbc with a batch file that will launch qb64 and compile your program, but for simplicity try
full-path-to-qb64 -x "%f"
last time I tried it, it would not highlight the lines containing errors, don't remember if it even would report the error line, that's why it would be good for you to write a batch file that will catch an error if there is one, if your program compiles successfully then you can click on the run button
also for non-ASCII language you probably need to make sure to BOM your document, click on Document->Write Unicode BOM