What DPI/PPI should a 4x64 by 6 meter outdoor billboard be donedesigned at?

I'm creating a 4x6meter4 x 6 meter (~13 x 20 feet) outdoor billboard advertisement that includes an image and vector logo (rasterized) in photoshopPhotoshop. I was working using a smaller size for design purposes, but now the client has approved a final design and wants to go to print. I need to know what DPI/PPI I should export it as.

Additionally, I was given advice by a friend to make it at 30 dpiDPI and work in centimeters (so 400x600cm400 x 600 cm) then let the print house blow it up to 4x6meters4 x 6 meters, is this true?

What DPI/PPI should a 4x6 meter outdoor billboard be done at?

I'm creating a 4x6meter outdoor billboard that includes an image and vector logo (rasterized) in photoshop. I was working using a smaller size for design purposes, but now the client has approved a final design and wants to go to print. I need to know what DPI/PPI I should export it as.

Additionally, I was given advice by a friend to make it 30 dpi and work in centimeters (so 400x600cm) then let the print house blow it up to 4x6meters, is this true?

What DPI/PPI should a 4 by 6 meter outdoor billboard be designed at?

I'm creating a 4 x 6 meter (~13 x 20 feet) outdoor billboard advertisement that includes an image and vector logo (rasterized) in Photoshop. I was working using a smaller size for design purposes, but now the client has approved a final design and wants to go to print. I need to know what DPI/PPI I should export it as.

Additionally, I was given advice by a friend to make it at 30 DPI and work in centimeters (so 400 x 600 cm) then let the print house blow it up to 4 x 6 meters, is this true?