Outdoor banner

I was asked to design an outdoor banner approx. 7’w x 20’h
I generated an image and want it to be the full length of the banner.
How can i make sure it will print clear? What should my document settings be and how should i save it?

I did once a strore front massive “banner”. The printer told me to create it 1:10 ratio, i would have been too big to create in Indesign in full size.

Also talk to the printer about what resolution it needs to be. Very often large banners can be lower ppi.