canvas size question.

Hi, im currently working on a project that requires a very large canvas. currently, photoshop will not create any canvas with pixel dimentions of over 30k x 30k. the only way i can currently fit my entire image is to drastically lower the image DPI, which i'm not willing to do. is there any way to change this limitation photoshop has, or if theres another program I can use to do this?

Lemme guess,
end product = billboard ?

As a rule of thumb you don't work on large scale products at scale.

Lower the physical size proportionaly and increase the resolution to compensate.