No service issue

[Sohel_rana]

Please tell us some basic information before asking for help:
Model Name:Asus z6
Firmware Version:ppr2.181005.003.ww_phone-16.1220.1906.167-0
Rooted or not:
Frequency of Occurrence:
APP Name & APP Version (If your issue relates to the app):
In addition to information above, please also provide as much details as you can, e.g., using scenario, what troubleshooting you've already done, screenshot, etc.
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My asus z6 not showing network signal.it can reads sim card but unable it's see network signali can't call or use mobile data.just i am to use wifi network.and when i switch on this device and here are showing such a notification.....

[Irene2_ASUS]

Hi @Sohel rana
You are running on a very old firmware, this could be causing the issue with your device's network. I recommend you to update it, you can do it manually just by downloading firmware version from our official support site: ZenFone 6｜Phones｜ASUS Global 
1.Since you are currently on an old version you will have to upgrade step by step to get to the newest version .156
2.Once you have downloaded each firmware version, I recommend you to back up your phone data, then connect to PC and copy the firmware file to the root directory of device “internal storage” (do not unzip it)
4.Disconnect the device from PC, then the notification icon will comes up in the status bar on top left corner.
5. Press the FW notification on top left corner to upgrade.
6.After installation is done you can then delete files

[Sohel_rana]

Is it possible to solve this problem without pc ...?