M 23, still not grown with proper beard. Less hairs in some areas.
Let me know if any cheap scientific way to grow facial hair by applying/taking any medicine?
Help me out as I want to look manly

Are you really 23 ? Sounds more 17, wanting to look manly,
Facial hair does not make or not make you look manly.

You are manly by various looks, often it may be more the clothes or even the way you carry yourself

I don't know of anything that will produce more facial hair. Some men are hairy, some are not.

If you're really concerned, you might check with your doctor to make sure you aren't lacking some hormones.

The best way to grow a fuller beard is to allow the beard to grown out completely for 6 weeks. After that time, shave your face clean. Repeat the process. You will experience a noticeable difference in the fullness of your beard.