Probably your device is not connected to the internet.
Check your WiFi Router / Modem for --> Recommended settings for Wi-Fi routers and access points ...
Connecting to Wi-Fi is the initial step, followed by establishing an internet connection.
However, it's important to note that connecting to Wi-Fi does not automatically guarantee an internet connection. In the event that you are unable to connect to Wi-Fi, the issue may stem from settings on your iPhone or the router/modem.
On the other hand, if you are unable to establish an internet connection despite being connected to Wi-Fi, the problem is likely related to the settings on your router/modem. In such cases, it is advisable to promptly contact your Internet Service Provider (ISP) for assistance.
For your Internet connection.
- Over Cellular: contact your Carrier (Cellular Service Provider). The agency that issued the SIM to you
- Over WiFI: Contact your ISP (Internet Service Provider), the agency that provided the Internet Service on your Modem/Router to you
You may --> Connect iPhone to the Internet - Apple Support