It is strongly recommended to use an engine that can export to the Web Browser, as executables are not curated and therefore not trustworthy, especially from unknown developers.
I make a personal rule for myself to only play Browser games on itch unless it is a game that has been around for awhile and there are no reports of maliciousness for a title.
For UE, there are UE4 versions that support HTML export, though I don't know much about limitations regarding the HTML exporting for UE4.