unable to activate

so i reset my iphone 7 because it said cellular data wasn't able to work on my device until updated, although my iphone wouldn't update for some reason so i thought it might work to just reset it. long story short, it didn't. after getting my phone ready to unlock after resetting it, it said it was unable to activate and didn't allow me to do anything other than to shut off my iphone.

any way to activate my phone again?

thanks:)