Allowing Third Party App Installation in Asus Zenfone Max Pro m2

Hello Guys,
I am unable to install Vidmate on My Asus Zenfone Max Pro M2 smartphone. Can anyone tell me what I am doing wrong? Or what is the solution to install it? I think it is because Vidmate is a third party app or is it because Asus Zenfone Max Pro M2 has stock android.
Please tell me how to unable third party installation in this phone.
Thanks and regards,
Aarohi