You can just make up some e-mail as, without internet, you couldn’t verify it. Also one of the rare cases where VPN directly improve your privacy.
They can track you even if you dont accept. Turn Wifi off. If you connect, use VPN home.
They can use your wifi signal as a beacon by triangulating the signal strength from at least 3 different points. Then they can figure out in which departments you spend the most time, how long you spend in store, heatmaps, which aisles you skip and generic info like what time you visit, which locations you also shop at.
A quick google for “Retail Wifi tracking” brings up mirame.net , where you can see some of the features.
I would suggest to set your phone to flight mode if you see a “free wifi” sign in your shopping mall.
