Is there any process to update the software without wi-fi

No.

Ask a friend, acquaintance or family to use their computer, or at a public library.

Alternately, visit your local Apple Store or Apple Authorized Service Provider and they should be able to help you out.

You will first have to make an appointment due to the pandemic.

See: Contact Apple for support and service

https://support.apple.com/en-us/HT201232

Hey there,

you can’t update your iPhone 7 without Wi-Fi network, but when you update your iPhone to iOS 15.4.1 you will be able to update it using cellular data!

also you will facing a problem with the update your iPhone wireless because your iOS version is older “ iOS 11” so I advise you to follow the steps in this link ☞ If your iPhone, iPad, or iPod touch won't update - Apple Support

You can connect your device to the computer and use iTunes to update: Update software on iPhone, iPad or iPod touch in iTunes on PC - Apple Support

Raicya wrote:

Only if OP has an iPhone 12 or 13 with a 5G connection than OP can update over the 5G network.

If your iPhone is running version 15.4, you'll be able to update it with cellular data (4G/LTE) whether it's iPhone 12/13 or earlier

Yes, I know that, I told him above [But when you update your iPhone to iOS 15.4.1 you will be able to update it using cellular data!] I meant to tell him that after updating to iOS 15.4.1 he will be able to update his iPhone To other versions using cellular data!

Looks like OP has not update to iOS 15.4 yet.

but when you update your iPhone to iOS 15.4.1 you will be able to update it using cellular data!

Only if OP has an iPhone 12 or 13 with a 5G connection than OP can update over the 5G network.