Apache htaccess redirect only root without change url root

Hi all,

I have a complex situation: myproject.com: is working fine both http and https running Yii2 web application

My client wants to integrate WordPress only for the main page, maintaining the rest of Yii2 web application

I create on the same host a new environment called wp.myproject.com where another user is building WordPress new main page (with other 2/3 static page for example the classic "contact us" or "about us")

What i need is that when visitors go on https://myproject.com it redirect to wp.myproject.com but the url must remain https://myproject.com

I search alot over the net but doesn’t find a good solution.

Can you help me? Thank’s