please guide how to make an ar app play video on canvas

hi all

i am a newbie here.. i have asgmt that have to submit using ar

my bos want to create ar.. and when the user scan the target image, it will be playing video on canvas.. with 2 buttons to choose video

can you guys help me.. guide me through the project.. i have refer to the youtube tutorial but there is lot error and i did not who to ask..

this is a simple project, others project will be according to this type of ar

i am using Unity 2018.4.3f1 (64-bit) with vuforia-unity package

please help me sir