HDMI Output does not work before booting the laptop

Hi guys,

My laptop runs almost perfectly on Mac, but recently i need to use an external monitor and the problem began. If i plug the external monitor to my laptop through hdmi before booting into MacOS, then the monitor would not work, i have to replug after the laptop completely boots. And that's so annoying.

Please give me a solution. I really can't find anything related to this problem. English is not my mother language, so be easy on me.

Some information about my "Mac" :

Dell Latitude 7390 - 8350u/uhd620/Catalina 10.15.6