If your phone is Android phone, then you can go to Settings –> Network & internet. Once you’ve found the Wi-Fi settings menu, go ahead and select it.
Scroll past the list of available networks and select the “Saved networks” option. From there, select one of the Wi-Fi networks your phone remembers.
Choose the “Share” option. You’ll be asked to scan your fingerprint or face or enter your PIN or password. Scan the QR code with another device using a QR scanner, but the password is also listed in plain text beneath the QR code, so you can copy it from there.
If you are using iPhone, then you can try to use a third-party tool such as findics.com, to find out your saved Wi-Fi password.
That’s all about my answer. I hope this will help you.