We’d need a lot more information to be able to answer you.
-What does “display an openstreetmap map” mean in your particular case? Is it a raster or vector rendering? Is it one you’ve created yourself or one being hosted by a third-party? What style is being used?
-What does “not displayed correctly” mean? Does it display but with the wrong style? Does it display partially? Does it not display at all?

So far, you’ve basically said “it doesn’t work” without specifying what “it” is or what “doesn’t work” means. Remember, we know nothing about your project, so you need to describe it to us.