I have a design I want to use on a fishing shirt .. question is how to I add the image as the shirt background/pattern

This is the Shirt Design I have >> This is the image I want to to cover the complete shirt .
My problem is I do not know how to do this and keep the shape of the shirt
Thanks in advance for any help
Cheers
Mick

This is the Shirt Design I have >> This is the image I want to to cover the complete shirt .
My problem is I do not know how to do this and keep the shape of the shirt
Thanks in advance for any help
Cheers
Mick