Rug creases help

[NailsHairNipsHeels]

Are there any tricks to flatten out a rug after it's delivered rolled up?
It's been out flat upside down and walked over for 3 days and right side up for 2 but still creased and bumpy.

Roll it up the other way round and put something heavy on it?

Carpet gripper underneath might help.

Dampen it?

Thanks for the suggestions. I waited for a dry day and hung it on my washing line and steamed the back.
It's not perfect but so much better.