My WiFi bar is not showing up but still it's connected

Try first to optimize the range of the mobile network, see this Apple article:

If you see No Service or Searching on your iPhone or iPad

If you see No Service or Searching on your iPhone or iPad - Apple Support

Optimize the Wi-Fi connection, see the following Apple articles:

Connect to Wi-Fi on your iPhone, iPad, or iPod touch

Connect to Wi-Fi on your iPhone, iPad, or iPod touch - Apple Support

If your iPhone, iPad, or iPod touch won’t connect to a Wi-Fi network

If your iPhone, iPad, or iPod touch won't connect to a Wi-Fi network - Apple Support

Recommended settings for Wi-Fi routers and access points

Recommended settings for Wi-Fi routers and access points - Apple Support

If you need help with your Wi‑Fi password

If you need help with your Wi‑Fi password - Apple Support

If they are On, turn Off Hotspot & VPN.

Try first to optimize the range of the mobile network, see this Apple article:

If you see No Service or Searching on your iPhone or iPad

If you see No Service or Searching on your iPhone or iPad - Apple Support

Recommended settings for Wi-Fi routers and access points

Recommended settings for Wi-Fi routers and access points - Apple Support

If you need help with your Wi‑Fi password

If you need help with your Wi‑Fi password - Apple Support

Charge the battery > 70%.

👉 There's no point in asking for help if you don't read the response you get.

Tap on the blue "i" next to the name of the wireless network for instructions on how to remedy the weak security that exists on your Wi-Fi network.

The "bars" appear to indicated that you have weak signal strength. Try locating the iPhone closer to the Wi-Fi router. Ideally, you would want line-of-sight between the iPhone and Wi-Fi router.