Wild flower roof garden

My downstairs neighbour has installed a large shopping container in our joint yard to keep his tools, bikes etc in. We have decided to plant a wild flower garden on the container roof to improve my view. Any suggestions for how we do this ?

 

Sorry I meant Shipping container

 

If you are trying to have a garden roof with alot of facilities like water and green grass then you can get your ideas expand from here https://felicita-flowers.com/en-gb/kiev/ which have more additional info about these thing of things so