In an accepted paper, I have written my acknowledgments to the funding entities and now I want to also acknowledge the fact that this work was mostly carried out in X place thanks to an internship Funding. However, I am not sure if I should phrase it like that or if there is a typical sentence in these cases.
Just keep it short and simple. If X provided the internship funding, make sure you say that. But focus, in any case, on the source of funds, not necessarily the place. What you wrote implies that X was the funder, which may be your intention. If it is otherwise, make it more clear.
If the internship has a specific name, mention that as well. "Roy and Dale Rogers Internship for the Study of Late Cowboy Culture".