[Risolto] How to assign main language to main page

Background of the issue:
I want to set bestmeditrips.com/en as my main page. My current main page is in 'page format' and not a post.

Symptoms:
Changes on the main menu are not applied to bestmeditrip.com but are applied to bestmeditrips.com/en.

Questions:
How can I set bestmeditrips.com/en as my main page?