how to turn off mobile data on iphone xs for phyiscal SIM

Turn cellular data on or off

To turn cellular data on or off, go to Settings, then tap Cellular or Mobile Data. If you're using an iPad, you might see Settings > Cellular Data. If you're using a Dual SIM iPhone, you need to set one of your plans as the primary data number in order to see how much cellular data you've used.

Depending on your carrier and device, you might have additional options listed under Cellular Data Options:

• Enable LTE, 4G, or 3G. You can select what type of network connection to use for voice and data. Learn more about these options.
• Turn Voice Roaming on or off: With CDMA networks, you can turn off Voice Roaming to avoid charges from using other carrier's networks.
• Turn Data Roaming on or off: When you're traveling internationally, you can turn off data roaming to avoid roaming charges. If you have an international data plan, you may need to keep Data Roaming on. Learn more about traveling internationally with your iPhone or iPad.

Depending on your carrier, data roaming might be used if you travel domestically. Contact your carrier for more information about your data roaming policy or other cellular data settings. You can turn cellular data on or off to limit apps and services from using the cellular network to connect to the Internet. When cellular data is on, apps and services use your cellular connection when Wi-Fi isn't available. As a result, you might be charged for using certain features and services with cellular data. Contact your carrier for more information about possible charges.

Check the cellular data usage on your iPhone and iPad - Apple Support

https://support.apple.com/en-in/HT201299

Using Dual SIM with an eSIM - Apple Support

https://support.apple.com/en-in/HT209044

About the LTE options on your iPhone

The cellular-data options on your iPhone might vary based on your carrier's network.

If your carrier supports VoLTE

On your iPhone, go to Settings > Cellular > Cellular Data Options and tap Enable LTE or Settings > Mobile Data and tap Enable LTE. If your carrier supports Voice over LTE (VoLTE), you'll see these options:

• Off: Turns off LTE
• Voice & Data: Allows voice calls and cellular-data use over LTE 
• Data Only: Allows cellular-data use, but not voice calls over LTE

If your carrier doesn't support VoLTE

If your carrier doesn't support VoLTE and is a GSM carrier, you'll see one of these options:

• LTE or 4G: Allows cellular-data use over the LTE or 4G network when available.
• 3G: Allows cellular-data use over the 3G network when available.
• 2G: Allows cellular-data use over the 2G network when available.

Depending on the wireless carrier, 4G can indicate either a UMTS or LTE connection. If your carrier doesn't support VoLTE and is a CDMA carrier, you'll only see an option to Enable LTE. This allows cellular-data use over the LTE network when available.