Unfortunately the HD Mod doesn't support Heroes Chronicles. Is there still a possibilty to change the resolution? F4 doesn't work.

You can use Heroes Chronicles with the HD Mod with some work.
You need to edit the campaign files, or more easily download a file called HC.rar, and then open the files as Custom Campaigns. Definitely worth it, IMO.

An easier method may be to use DgVoodoo.

https://verokster.blogspot.com/2018/10/heroes-of-might-and-magic-i-iv-gl.html

scroll down for the Heroes 3 + Chronicles download